Billet handling systems for shear assisted extrusion

Abstract

The present disclosure provides a dummy block for a shear assisted direct extrusion press. The dummy block comprises a mandrel comprising a first end and a second end, wherein the first end comprises a surface configured to interface with a billet. The surface comprises a plurality of structures protruding from the surface, wherein the plurality of structures are configured to protrude into the billet during a shear assisted direct extrusion process to transmit rotational torque from the dummy block to the billet. The mandrel may have a tapered shape with the first end having a larger diameter than the second end. The plurality of structures may comprise shapes including cross-spade configurations, arced cross-spade arrangements, spreader dished patterns, spreader domed geometries, or protruding cones. The structures include rounded corners where the structures intersect with the surface to facilitate insertion and retraction operations.

Description

BILLET HANDLING SYSTEMS FOR SHEAR ASSISTED EXTRUSIONCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Application No. 63 / 707,122, titled “Billet Sample Handling and Components,” filed October 14, 2024, which is hereby incorporated by reference in its entirety.FIELD OF INVENTION

[0002] The present disclosure relates to extrusion press components for metal forming processes, and more particularly to dummy block assemblies with specialized surface structures for transferring torque in shear assisted direct extrusion processes.BACKGROUND

[0003] Metal extrusion processes are widely used in manufacturing to form complex profiles and shapes from various metallic materials. In conventional direct extrusion, a billet of material is pushed through a die using a ram or pressing stem to create the desired cross-sectional shape. The process typically requires substantial forces and elevated temperatures to achieve the plastic deformation needed for material flow through the die.

[0004] Traditional extrusion systems rely on dummy blocks positioned between the pressing stem and the billet to transmit axial forces during the extrusion process. These dummy blocks serve as intermediary components that distribute the pressing forces uniformly across the back surface of the billet while maintaining proper sealing within the container. Conventional dummy blocks generally feature relatively smooth interface surfaces that contact the billet material.

[0005] Shear assisted extrusion represents an advancement in metal forming technology that combines both axial and rotational forces during the extrusion process. This approach applies simultaneous linear pressing and rotational shearing to the material, creating severe plastic deformation that can refine microstructures and enable processing of materials that are difficult to extrude using conventional methods. The combined deformation mechanisms can result in improved material properties and allow for lower processing temperatures compared to traditional extrusion techniques.

[0006] The scaling of shear assisted extrusion processes from laboratory to commercial production introduces new challenges related to force transmission and torque transfer. Commercial-scale operations require substantially higher forces and torques compared to smaller laboratory systems, with torque requirements potentially increasing by more than an order of magnitude. The effective transfer of both axial forces and rotational torque from the pressing system to the billet becomes increasingly challenging as the scale of operation increases.SUMMARY

[0007] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0008] According to an aspect of the present disclosure, a dummy block is provided. The dummy block comprises a mandrel comprising a first end, wherein the first end comprises a surface configured to interface with a billet. The surface comprises a plurality of structures protruding from the surface, wherein the plurality of structures are configured to protrude into the billet during a shear assisted direct extrusion process.

[0009] According to other aspects of the present disclosure, the dummy block may include one or more of the following features. The mandrel may have a tapered shape,wherein the first end has a larger diameter than an opposite end of the mandrel. The plurality of structures may comprise a shape selected from the group consisting of: a cross-spade shape, a cross-spade with 45° spades shape, an arced cross-spade shape, an S blend cross-spade shape, a spreader dished shape, a spreader domed shape, and a plurality of protruding cones. The dummy block may be configured to be loaded into a container of a shear assisted direct extrusion press, and an opposite end from the first end of the mandrel may be configured to connect with a ram. The dummy block may transmit a torque from the ram to the billet. The torque may be greater than or equal to 20 MN. The ram, the dummy block, the billet, and the container may rotate during the shear assisted direct extrusion process, wherein the ram, the dummy block, and the billet move axially during the shear assisted direct extrusion process. The dummy block may comprise a material selected from the group consisting of: a steel, a carbon steel, an alloy steel, a tool steel, a hot-work tool steel, a cold-work tool steel, and a high-speed steel. The shear assisted direct extrusion process may extrude a part of a diameter greater than or equal to 7 inches. The billet may comprise a metal selected from the group consisting of: aluminum, iron, copper, silicon, magnesium, manganese, and zinc. The billet may comprise an aluminum alloy selected from the group consisting of: a 3xxx series aluminum alloys, a 5xxx series aluminum alloy, a 6xxx series aluminum alloy, and a 7xxx series aluminum alloy. The billet may comprise a metallic material in a form selected from the group consisting of: powder, flake, scrap and solid.

[0010] According to another aspect of the present disclosure, a shear assisted direct extrusion process is provided. The process comprises applying an axial and rotational movement to a dummy block via a ram of a shear assisted direct extrusion press, wherein the dummy block comprises: a mandrel comprising a first end, wherein the first end comprises a surface configured to interface with a billet; wherein the surface comprises a plurality of structures protruding from the surface, wherein the plurality of structures areconfigured to protrude into the billet during the shear assisted direct extrusion process; and extruding a part from the billet by transmitting the axial and rotational movement from the dummy block to the billet.

[0011] According to other aspects of the present disclosure, the process may include one or more of the following features. The mandrel may have a tapered shape, wherein the first end has a larger diameter than an opposite end of the mandrel. The plurality of structures may comprise a shape selected from the group consisting of: a cross-spade shape, a cross-spade with 45° spades shape, an arced cross-spade shape, an S blend cross-spade shape, a spreader dished shape, a spreader domed shape, and a plurality of protruding cones. The dummy block may be configured to be loaded into a container of a shear assisted direct extrusion press, and an opposite end from the first end of the mandrel may be configured to connect with the ram. The dummy block may transmit a torque from the ram to the billet. The torque may be greater than or equal to 20 MN. The ram, the dummy block, the billet, and the container may rotate during the shear assisted direct extrusion process, wherein the ram, the dummy block, and the billet move axially during the shear assisted direct extrusion process. The dummy block may comprise a material selected from the group consisting of: a steel, a carbon steel, an alloy steel, a tool steel, a hot-work tool steel, a cold-work tool steel, and a high-speed steel. The part may have a diameter greater than or equal to 7 inches. The billet may comprise a metal selected from the group consisting of: aluminum, iron, copper, silicon, magnesium, manganese, and zinc. The billet may comprise an aluminum alloy selected from the group consisting of: a 3xxx series aluminum alloys, a 5xxx series aluminum alloy, a 6xxx series aluminum alloy, and a 7xxx series aluminum alloy. The billet may comprise a metallic material in a form selected from the group consisting of: powder, flake, scrap and solid.

[0012] Additional embodiments and features are set forth in part in the description that follows, and in part will become apparent to those skilled in the art upon examinationof the specification or may be learned by the practice of the disclosure. A further understanding of the nature and advantages of the present disclosure may be realized by reference to the remaining portions of the specification and the drawings, which forms a part of this disclosure.BRIEF DESCRIPTION OF FIGURES

[0013] The description will be more fully understood with reference to the following figures, which are presented as embodiments of the invention and should not be construed as a complete recitation of the scope of the invention, wherein:

[0014] FIG. 1 A illustrates a cross-sectional view of a direct extrusion press according to prior art.

[0015] FIG. 1 B shows a flowchart of a direct extrusion process according to prior art.

[0016] FIG. 2A shows a cross-section view of a dummy block assembly according to prior art.

[0017] FIG. 2B shows a cross-section view of the dummy block assembly of FIG. 2A.

[0018] FIG. 2C shows an exploded view of the dummy block assembly of FIG. 2A.

[0019] FIG. 2D shows a perspective view of a dummy block assembly with a billet interface surface.

[0020] FIG. 3A shows a perspective of dummy block assembly for shear assisted extrusion in accordance with various embodiments.

[0021] FIG. 3B shows a perspective view of the dummy block of FIG. 3A with inverted relief angle in accordance with various embodiments.

[0022] FIG. 4A shows a front perspective of dummy block assembly and mandrel for shear assisted extrusion in accordance with various embodiments.

[0023] FIG. 4B shows a rear perspective of the dummy block assembly and mandrel of FIG. 4A in accordance with various embodiments.

[0024] FIG. 5 shows a cross-section view of a dummy block assembly and mandrel in accordance with various embodiments.

[0025] FIGs. 6A to 6C show perspective views of a locking element for mating a stem and a dummy block assembly in accordance with various embodiments.

[0026] FIG. 7A shows front and perspective views of a mandrel with cross-spade surface structures in accordance with various embodiments.

[0027] FIG. 7B shows front and perspective views of a mandrel with cross-spade and 45° spade surface structures in accordance with various embodiments.

[0028] FIG. 7C shows front and perspective views of a mandrel with arced crossspade surface structures and rotation direction in accordance with various embodiments.

[0029] FIG. 7D shows front and perspective views of a mandrel with S blend crossspade surface structures and directional arrows in accordance with various embodiments.

[0030] FIG. 7E shows front and perspective views of a dummy block assembly with spreader dished surface structures in accordance with various embodiments.

[0031] FIG. 7F shows front and perspective views of a mandrel with spreader domed surface structures and rotation arrows in accordance with various embodiments.

[0032] FIG. 7G shows front and perspective views of a mandrel with protruding cone surface structures in accordance with various embodiments.DETAILED DESCRIPTION

[0033] The following description sets forth exemplary aspects of the present disclosure. It should be recognized, however, that such description is not intended as a limitation on the scope of the present disclosure. Rather, the description alsoencompasses combinations and modifications to those exemplary aspects described herein.

[0034] It will be understood that the components of the embodiments, as generally described herein and illustrated in the appended figures, may be arranged and designed in a variety of different configurations. Thus, the following more detailed description of various embodiments, as represented in the figures, is not intended to limit the scope of the present disclosure but is merely representative of various embodiments. While various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

[0035] The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive.

[0036] Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present invention should be or are in any single embodiment of the invention. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, discussions of the features and advantages and similar language throughout this specification may, but do not necessarily, refer to the same embodiment.

[0037] Furthermore, the described features, advantages, and characteristics of the invention may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize, in light of the description herein, that the invention can be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the invention.

[0038] Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, orcharacteristic described in connection with the indicated embodiment is included in at least one embodiment. Thus, the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may but do not necessarily, all refer to the same embodiment.

[0039] Shear assisted extrusion processes combine linear and rotational forces to create severe deformation in metallic feedstock materials during extrusion operations. The combination of these deformational forces may result in metal extrusions with refined microstructural grain structures and improved mechanical properties compared to conventional extrusion processes. In some cases, the deformation induced during shear assisted extrusion processes may refine and disperse intermetallic compounds that are commonly found in post-consumer scrap materials, allowing for the use of recycled materials as feedstocks for extruded products.

[0040] Billet sample handling systems and components play a role in shear assisted extrusion processes by facilitating the transfer of forces and torques from the extrusion press machinery to the metallic feedstock. In some cases, these systems may include dummy blocks that interface directly with the billet material and transmit both axial and rotational forces during the extrusion process. The design and configuration of billet handling components may affect the efficiency of force transmission and the quality of the resulting extruded products.

[0041] Commercial scale shear assisted extrusion operations may involve significantly higher forces and torques compared to laboratory scale processes. In some cases, the scaling of shear assisted extrusion processes from laboratory to commercial production may introduce system requirements for extrusion force, torque, time scale, and temperature that exceed the capabilities of conventional billet handling components. The increased force and torque requirements may necessitate specialized designs fordummy blocks and related components to ensure effective force transmission and prevent slipping between the dummy block and billet interface.

[0042] Billet sample handling systems for shear assisted extrusion may accommodate various types of metallic feedstock materials, including aluminum alloys, recycled scrap materials, and other metal compositions. In some cases, the handling systems may be configured to work with billets having different thermal properties and mechanical characteristics. The design of billet handling components may take into account the softened state of preheated billets and the need to maintain structural integrity under high temperature and high force operating conditions.

[0043] Referring to Figure 1 A, conventional direct extrusion press systems may include several components arranged to facilitate the extrusion of metallic materials. In some cases, a container and container liner may be positioned to house a billet during the extrusion process. A pressing stem may extend through one end of the assembly to provide the driving force for the extrusion operation. The pressing stem may be configured to apply axial force to move the billet through the extrusion system. A die and die backer may be positioned at the opposite end from the pressing stem to shape the extruded material as the billet passes through the die opening. A dummy block may be located between the pressing stem and the billet to transmit forces from the pressing stem to the billet material.

[0044] In conventional direct extrusion processes, the billet may move axially while the container remains stationary in the axial direction. The outer surface of the billet may move relative to the container wall as the extrusion proceeds, creating shear at the billetcontainer interface. In some cases, lubricant may be applied during direct extrusion to reduce friction between the billet and container surfaces. Part of the extrusion load may be expended in overcoming friction between the billet and container or in shearing the inner material from the slower-moving peripheral layer adjacent to the container wall. Thedummy block may serve as an extension of the pressing stem and may transmit the force of the stem to the billet while pushing the softened billet through the die.

[0045] With reference to Figure 1 B, conventional direct extrusion processes may follow a sequence of preparation and operational steps. The process may begin with a step 101 that involves preheating portions of the extrusion press, including the container and dummy block components. In some cases, the container and dummy block may be heated to temperatures of at least about 400°F to reduce the time required for the extrusion process. Following the initial heating, a step 102 may comprise preheating and loading the die assembly into the extrusion press. The die and die assembly may be heated to temperatures that are greater than, equal to, or less than the temperature of the container and dummy block, depending on the specific process requirements.

[0046] The extrusion process may continue with a step 103 where the billet may be preheated and loaded into the container. Preheating the billet may shorten the extrusion process and reduce heat loss during the operation. In some cases, the billet may be heated to a temperature that is greater than, equal to, or less than the temperature of the container and dummy block. When the billet reaches the desired temperature, the billet may be loaded into the container for processing. The process may then proceed to a step 104 where the extrusion process may be started. During conventional extrusion operations, the dummy block may need to ensure a tight seal within the extrusion press and may affect both extrusion quality and press performance through the interaction between the dummy block and container, as well as the interface between the dummy block and billet.

[0047] The introduction of shear forces to conventional extrusion systems may create complications in the force transmission between the dummy block and billet. In shear assisted extrusion processes, both the pressing stem and dummy block may rotate while under load, which may introduce rotational forces that conventional dummy block designsmay not be configured to handle effectively. The rotating stem and dummy block may need to prevent slipping between the dummy block and the back of the billet to ensure proper torque transfer. Conventional dummy blocks with relatively smooth surface finishes may not provide adequate interfacial contact area to transmit the combined axial and rotational forces required for shear assisted extrusion. In some cases, the preheated billet material may have sufficiently low yield strength that conventional dummy block designs may not effectively transfer rotational torque to the billet, potentially causing the billet to be stirred from the back end rather than rotated as a unified mass.

[0048] Referring to Figures 2A, 2B, and 2C, conventional dummy block assemblies may include multiple component parts that work together to facilitate force transmission during extrusion operations. In some cases, these assemblies may be configured as replaceable ring block (RRB) type dummy block systems that allow for maintenance and replacement of individual components. A holder 1 may serve as the main structural component of the dummy block assembly and may provide the primary connection interface with the pressing stem. The holder 1 may be designed to accommodate other components of the assembly while maintaining structural integrity under the forces encountered during extrusion operations. A replaceable expansion ring 2 may be positioned within the holder 1 and may be configured to provide a sealing interface with the container during extrusion. The expansion ring 2 may be designed as a replaceable component to allow for maintenance and replacement when wear occurs during operation.

[0049] A mandrel 3 may be positioned to extend through the expansion ring 2 and may serve as the primary interface component with the billet material. The mandrel 3 may be secured within the assembly through connection with other components and may be responsible for transmitting forces from the pressing stem to the billet. A mandrel nut 4 may connect with the mandrel 3 to secure the mandrel 3 within the assembly and mayprovide a threaded connection that allows for adjustment and maintenance of the mandrel 3 position. The assembly may also include a bayonet stud 5 that may work in conjunction with other components to provide mechanical connections within the dummy block system. A spring 6 may be incorporated into the assembly to provide spring-loaded mechanisms that may facilitate engagement and disengagement of the dummy block with the billet material. In some cases, the spring 6 may work with the bayonet stud 5 to create a spring mechanism that allows for controlled movement of components during operation.

[0050] The dummy block assembly may include several alignment and securing components that may ensure proper positioning and operation of the system. A locating pin 7 may aid in the proper alignment of components within the assembly and may prevent misalignment during assembly or operation. The locating pin 7 may be positioned to engage with corresponding features in other components to maintain proper orientation. A dowel pin 8 may provide additional structural support and alignment within the assembly and may work in conjunction with the locating pin 7 to ensure accurate positioning of components. A stud pin 9 may be incorporated to provide additional securing functionality within the assembly and may work with other fastening components to maintain the integrity of the dummy block system. A retaining screw 10 may be used to secure components together and may provide a removable fastening mechanism that allows for disassembly and maintenance of the dummy block assembly when needed.

[0051] With reference to Figure 2D, conventional dummy block designs may feature relatively simple interface configurations with the billet material. A mandrel body 201 may have a generally cylindrical shape and may be configured to fit within the container of the extrusion press. The mandrel body 201 may be designed to withstand the axial forces encountered during conventional extrusion operations and may be manufactured from materials suitable for high-temperature and high-force applications. At one end of the mandrel body 201 , a billet interface surface 202 may be configured to contact the billetduring the extrusion process. The billet interface surface 202 may have a diameter that may be sized to match the diameter of the billet and may be designed to fit within the tolerances of the container. In conventional dummy block designs, the billet interface surface 202 may have a relatively smooth surface finish that may be suitable for conventional extrusion operations where only axial forces are transmitted to the billet.

[0052] The conventional dummy block assemblies shown in Figures 2A, 2B, 2C, and 2D may be designed for traditional extrusion processes where the primary force transmission may be axial in nature. In some cases, the tapered body configurations of conventional mandrels may be inserted into a ring or replaceable expansion ring to ensure tight clearance during engagement with the billet and open clearance during retraction of the dummy block after extrusion. The spring mechanisms and expansion ring systems may be designed to accommodate the thermal expansion that occurs during preheating operations and may provide sealing functionality during the extrusion process. However, conventional dummy block designs may not be configured to handle the additional rotational forces and torques that may be encountered in shear assisted extrusion processes. The smooth interface surfaces and conventional component arrangements may not provide adequate interfacial contact area or mechanical engagement to effectively transmit both axial and rotational forces to the billet material, potentially leading to slipping or inadequate torque transfer during shear assisted extrusion operations.

[0053] Many embodiments of the specification describe dummy block assemblies configured to operate in shear assisted extrusion presses. Referring to Figures 3A and 3B, specialized geometric features may be incorporated into dummy block designs to address operational challenges associated with the engagement and disengagement cycles of shear assisted extrusion processes. Figure 3A illustrates a dummy block assembly 301 that may integrate various surface design configurations for interfacing withbillet materials during shear assisted extrusion operations. The dummy block assembly 301 may have a compression ring 302 and stem holding portion 303 disposed at one end of the dummy block assembly that are cooperatively configured to accommodate a mandrel (not shown) having specialized surface geometries described in connection with the figures below designed to operate in shear assisted extrusion. Dummy block assemblies may also incorporate additional design features that may enhance the operational reliability of the system. In some cases, the compression ring portion 302 of the dummy block assembly 301 may be designed to work with the other components of the dummy block assembly system, described in relation to FIG. 1 , to provide comprehensive force transmission capabilities during commercial scale extrusion operations. The dummy block assembly 301 may be manufactured from materials such as steel, carbon steel, alloy steel, tool steel, cold-work tool steel, hot-work tool steel, or high-speed steel that can maintain structural integrity under the high-temperature and high-force conditions encountered during shear assisted extrusion processes.

[0054] Figure 3B illustrates an enlarged cross-sectional view of the dummy block assembly 301 that reveals internal geometric features designed to facilitate proper operational cycling during shear assisted extrusion processes. The cross-sectional view may show the internal structure of the dummy block assembly 301 and may reveal design elements that may not be apparent from external views of the component. In some cases, the cross-sectional representation may provide detailed information about the geometric relationships between different portions of the dummy block assembly 301 and may illustrate how specialized features may be integrated into the overall design of the component. The enlarged view may allow for examination of dimensional relationships and geometric transitions that may affect the performance of the dummy block assembly 301 during engagement and disengagement operations with billet materials. The cross- sectional perspective may also reveal manufacturing considerations and design featuresthat may contribute to the operational effectiveness of the dummy block assembly 301 under the demanding conditions of commercial scale shear assisted extrusion processes.

[0055] The compression ring 302 of the dummy block assembly 301 may incorporate an inverted relief angle 304 that may be positioned within the internal geometry of the compression ring 302 of the dummy block to address specific operational challenges associated with the retraction phase of the extrusion cycle. The inverted relief angle 304 may be configured as a geometric feature that may facilitate the return of the dummy block assembly 301 to its original shape after deformation that may occur during high- force engagement with billet materials. In some cases, the inverted relief angle 304 may be designed to counteract the effects of thermal expansion and mechanical deformation that may occur during the extrusion process, which may otherwise cause the dummy block assembly 301 to maintain a deformed configuration that could interfere with proper retraction operations. The inverted relief angle 304 may be positioned at specific locations within the dummy block assembly 301 where deformation may be most likely to occur during engagement with softened billet materials under high-temperature and high-force conditions. The geometric configuration of the inverted relief angle 304 may be optimized to provide the appropriate restoring forces that may help the dummy block assembly 301 return to its original dimensional configuration after the completion of the extrusion process.

[0056] The inverted relief angle 304 of the compression ring 302 may function to prevent sticking between the dummy block assembly 301 and the billet material during the retraction phase of the extrusion cycle. In some cases, the high temperatures and pressures encountered during shear assisted extrusion operations may cause the dummy block assembly 301 and billet material to form temporary bonds or mechanical interlocks that could interfere with the separation of the components after the extrusion process may be completed. The inverted relief angle 304 may create geometric conditions that mayfacilitate the breaking of these temporary bonds by providing clearance spaces or stress relief areas that may allow the dummy block assembly 301 to separate cleanly from the billet material. The inverted relief angle 304 may be designed to work in conjunction with the expansion ring 2 and spring 6 mechanisms of the overall dummy block assembly to ensure that the dummy block assembly 301 can be retracted smoothly without causing damage to either the dummy block assembly 301 or the remaining billet material. In some cases, the inverted relief angle 302 may help maintain the dimensional stability of the dummy block assembly 301 throughout multiple extrusion cycles by preventing permanent deformation that could accumulate over repeated use.

[0057] Referring to Figures 4A and 4B, the compression ring 402 and stem holder403 of the dummy block assembly 401 may be configured to be cooperative with the stem 407 and taper external surfaces 410 of the mandrel 404 such that the mandrel is securely engaged with the dummy block assembly 401 . To further prevent rotation of the mandrel404 relative to the dummy block assembly 401 and ensure the shear forces are fully transmitted through the mandrel 404 and interface surfaces 405 into the billet, cooperative locking elements on the mandrel 406 and dummy block assembly 408 may be disposed on the dummy block assembly 401 .

[0058] As shown, the mandrel 404 may be positioned within the dummy block assembly and may serve as a structural component that houses the surface geometry configurations while preventing rotation of other components in the die stack during shear assisted extrusion operations. The compressing ring 402 and overall dummy block assembly may be designed to withstand the torsional forces generated during rotational extrusion processes while maintaining proper alignment with the container and die assembly components. In some cases, dummy block assembly 401 may provide a mounting interface for mandrel components and may facilitate the integration of specialized surface configurations into the overall dummy block assembly. The dummyblock assembly and mandrel may be manufactured from materials suitable for high- temperature and high-torque applications, such as tool steels or other alloy compositions that can maintain structural integrity under the demanding conditions of commercial scale shear assisted extrusion processes.

[0059] A mandrel body 404 may be positioned within the dummy block assembly 401 and may have a tapered shape that transitions from a larger diameter at the billet interface end to a smaller diameter at the connection end. The mandrel body 404 may be configured to fit within the compression ring 402 and may provide sealing functionality during extrusion operations while accommodating thermal expansion that occurs during preheating of the dummy block components. In some cases, the tapered configuration of the mandrel body 404 may ensure tight clearance when engaging the dummy block assembly with the billet during extrusion operations and may provide open clearance when retracting the dummy block after the extrusion process may be completed. The mandrel body 404 may be designed to transmit both axial and rotational forces from the pressing stem to the billet material through the specialized surface configurations positioned at the billet interface end. The structural design of the mandrel body 404 may accommodate the high forces and torques associated with commercial scale shear assisted extrusion while maintaining dimensional stability under elevated temperature conditions.

[0060] The mandrel body 404 may feature a protruding surface 405 that may be positioned at the billet interface end and may be configured to contact and engage with the billet material during shear assisted extrusion processes. The protruding surface 405 may include a plurality of protruding structures that may extend from the base surface to create mechanical engagement with the softened billet material through discrete contact points distributed across the interface area. In some cases, the protruding surface 405 may be designed to maximize the interfacial contact area between the billet and themandrel body 404 while providing multiple penetration points that can effectively transmit rotational forces to the billet material. The surface configuration of the protruding surface 405 may accommodate the complex deformation patterns that occur in softened billet materials during high-temperature extrusion operations while maintaining consistent contact throughout the rotational cycle. The protruding surface 405 may be manufactured with surface finishes and geometries that facilitate both effective billet penetration during engagement and clean separation during retraction operations.

[0061] As shown in Figure 5, the implementation of the inverted relief angle 506 may involve specific geometric relationships between different portions of the dummy block assembly 501 that may optimize the balance between engagement effectiveness and retraction reliability. The inverted relief angle 506 of the compression ring 407 may be positioned relative to interface surface configurations 508 of mandrels 502 to ensure that the specialized interface surface geometries of such mandrels can effectively engage with billet materials while maintaining the ability to disengage cleanly after the extrusion process. In some cases, the inverted relief angle 506 may be integrated with the tapered body configurations of the dummy block assembly 501 to create a comprehensive geometric system that may accommodate both the thermal expansion that occurs during preheating operations and the mechanical deformation that may occur during high-force engagement with billet materials. The inverted relief angle 506 may be designed to work with the mandrel 502, mandrel nut, and other components of the dummy block assembly to ensure that the overall system can maintain proper dimensional relationships throughout the complete extrusion cycle. The geometric parameters of the inverted relief angle 506 may be optimized based on the specific material properties of the dummy block assembly 501 , the expected operating temperatures and forces, and the characteristics of the billet materials that may be processed during commercial scale shear assisted extrusion operations. To further prevent rotation of the mandrel 502 relative to the dummyblock assembly 501 and ensure the shear forces are fully transmitted through the mandrel 502 and interface surfaces 508 into the billet, cooperative locking elements on the mandrel 505 and dummy block assembly 504 may be disposed on the dummy block assembly 501 when the stem 503 is positioned within the stem holder 509.

[0062] Turning to the overall configuration of mandrels, as shown, tapered mandrel configurations may provide enhanced operational characteristics for dummy block assemblies used in shear assisted extrusion processes by facilitating controlled engagement and disengagement with billet materials under varying thermal and mechanical conditions. The tapered geometry may be implemented in mandrel designs where the mandrel may have a shape that transitions from one diameter to another diameter along the axial length of the component. As shown in Figures 4 and 5, some cases, the tapered mandrel may have a first end that may have a larger diameter compared to an opposite end of the mandrel, creating a conical or frustoconical profile that may accommodate the operational requirements of the extrusion system. The diameter transition may be gradual along the length of the mandrel, creating a smooth geometric progression that may distribute mechanical stresses and thermal expansion effects across the component structure. The tapered configuration may be designed to optimize the balance between sealing effectiveness during extrusion operations and ease of retraction after the completion of the extrusion cycle.

[0063] The larger diameter first end of the tapered mandrel may be positioned at the billet interface location where the mandrel may contact and engage with the billet material during shear assisted extrusion processes. The increased diameter at the first end may provide enhanced contact area with the billet material, which may improve the effectiveness of force transmission between the mandrel and the billet during both axial and rotational loading conditions. In some cases, the larger diameter may accommodate the specialized surface configurations that may be incorporated into the billet interface,such as protruding structures or other geometric features that may enhance torque transmission capabilities. The first end diameter may be sized to match the internal diameter of the container system while maintaining appropriate clearances for thermal expansion that may occur during preheating operations. The opposite end of the mandrel may have a smaller diameter that may facilitate connection with other components of the dummy block assembly, such as stem connectors or mounting hardware that may interface with the pressing stem system.

[0064] The tapered geometry may facilitate integration with compression ring mechanisms that may be incorporated into dummy block assemblies to provide sealing and clearance control during extrusion operations. The expansion ring may be positioned around the tapered mandrel and may be configured to accommodate the changing diameter of the mandrel along its axial length. In some cases, the expansion ring may be designed to engage with the tapered mandrel at specific locations along the taper to provide controlled sealing pressure against the container wall during extrusion operations. The tapered mandrel may be inserted into the expansion ring in a manner that allows the ring to expand or contract in response to the changing diameter of the mandrel, which may provide variable sealing characteristics that may be optimized for different phases of the extrusion cycle. The interaction between the tapered mandrel and the expansion ring may create a sealing system that may accommodate thermal expansion of both components while maintaining effective sealing against the container during high- temperature operations.

[0065] The tapered mandrel configuration may ensure proper clearance characteristics during both engagement and retraction phases of the extrusion operation by providing controlled dimensional relationships that may change as the mandrel moves axially within the container system. During the engagement phase, the tapered mandrel may be inserted into the container with the larger diameter first end leading the insertionprocess, which may create progressively tighter clearances as the mandrel advances toward the billet material. The tapered geometry may allow the mandrel to establish initial contact with the billet material through the larger diameter first end while maintaining appropriate clearances between the smaller diameter portions of the mandrel and the container wall. In some cases, the progressive diameter change may create a wedging action that may help the mandrel penetrate into the softened billet material while distributing the insertion forces over the tapered surface area. The engagement process may be facilitated by the gradual diameter transition, which may reduce the insertion forces compared to constant diameter configurations that might create abrupt contact conditions.

[0066] During the retraction phase of the extrusion operation, the tapered mandrel configuration may provide enhanced disengagement characteristics by creating progressively increasing clearances as the mandrel may be withdrawn from the container system. The withdrawal process may begin with the smaller diameter opposite end of the mandrel, which may create initial clearance that may facilitate the breaking of any temporary bonds or mechanical interlocks that may have formed between the mandrel and the billet material during the high-temperature extrusion process. As the mandrel continues to retract, the progressively larger diameter portions may disengage from the billet material in a controlled manner that may reduce the likelihood of damage to either the mandrel or the remaining billet material. In some cases, the tapered geometry may work in conjunction with expansion ring mechanisms to provide controlled clearance expansion that may facilitate smooth retraction even when thermal expansion or mechanical deformation may have occurred during the extrusion process. The tapered configuration may help prevent sticking or binding that might otherwise occur with constant diameter mandrel designs, particularly under the high-temperature and high- force conditions associated with commercial scale shear assisted extrusion operations.

[0067] The dimensional parameters of the tapered mandrel may be optimized to accommodate the specific thermal expansion characteristics of the mandrel material and the operating temperature ranges encountered during shear assisted extrusion processes. The taper angle may be selected to provide appropriate clearance progression while maintaining structural integrity under the axial and rotational forces that may be transmitted through the mandrel during extrusion operations. In some cases, the taper angle may be designed to compensate for differential thermal expansion between the mandrel and the container system, which may help maintain consistent clearance relationships throughout the temperature range of the extrusion process. The length of the tapered section may be proportioned relative to the overall mandrel length to provide adequate clearance control while maintaining sufficient structural cross-section to handle the transmitted forces. The tapered mandrel configuration may be manufactured using machining processes that can maintain precise dimensional tolerances along the tapered surface, which may ensure consistent performance characteristics across multiple extrusion cycles and may facilitate predictable engagement and retraction behavior under varying operational conditions.

[0068] Referring to Figures 6A to 6C, to ensure that the dummy block assembly 605 engages with the stem 601 of the extrusion press to allow rotational shear forces to be transmitted through the dummy block assembly, a stem locking element 603 may be provided that cooperatively engages stem locking cavities formed in the rear surface 604 of the dummy block assembly 605 and the front surface 602 of the stem 601. It will be understood that the tolerances of the cooperative key and locking cavities are formed to ensure full transmission of the stem to the dummy block assembly. The key and locking cavities may be manufactured from materials suitable for high-temperature and high- torque applications, such as tool steels or other alloy compositions that can maintainstructural integrity under the demanding conditions of commercial scale shear assisted extrusion processes.

[0069] Referring to Figure 7A, shear assisted extrusion processes may utilize mandrels with specialized surface configurations to facilitate effective torque transmission between the pressing stem and billet material. A mandrel 710 may include a stem connector 711 that may be configured to connect with the dummy block assembly described in Figures 3 to 6 of the dummy block system. The stem connector 711 may provide a mechanical interface that allows the mandrel 710 to receive both axial and rotational forces from the pressing stem during shear assisted extrusion operations. The mandrel 710 may also include a tapered body 712 that may transition from a larger diameter at one end to a smaller diameter at the stem connector 711 . The tapered body 712 may be designed to fit within the expansion ring of the dummy block assembly and may provide sealing functionality during extrusion while allowing for thermal expansion of the components during preheating operations.

[0070] The mandrel 710 may feature an interface surface 713 that may be configured to contact the billet material during shear assisted extrusion processes. The interface surface 713 may include a plurality of protruding structures that may extend from the surface to engage with the softened billet material. In some cases, the protruding structures may comprise protruding arms 714 that may be arranged in a cross-spade pattern across the interface surface 713. Each protruding arm 714 may have a triangle cross-section configuration where the triangular profile may create a pointed edge that can penetrate into the preheated billet material. The tips of the triangle cross-sections may merge at the center of the interface surface 713, creating a unified structure that may distribute forces across the billet interface. The cross-spade arrangement of the protruding arms 714 may provide multiple contact points with the billet material, whichmay increase the interfacial area between the mandrel 710 and the billet compared to conventional smooth interface surfaces.

[0071] The protruding arms 714 may include rounded corners 715 where the arms intersect with the interface surface 713. The rounded corners 715 may facilitate the insertion of the mandrel 710 into the softened billet material during engagement and may also aid in the retraction of the mandrel 710 from the billet material after the extrusion process may be completed. In some cases, the rounded corners 715 may reduce stress concentrations that might otherwise occur at sharp transitions between the protruding arms 714 and the interface surface 713. The combination of the triangle cross-section profile of the protruding arms 714 and the rounded corners 715 may allow the mandrel 710 to penetrate into the billet material while maintaining structural integrity under the high forces and temperatures encountered during shear assisted extrusion operations. The cross-spade configuration may maximize the interfacial contact area between the billet and the mandrel 710, which may ensure effective torque transfer and rotation of the billet material during the extrusion process.

[0072] With reference to Figure 7B, alternative configurations of mandrels may incorporate additional structural features to enhance torque transmission capabilities. A mandrel 720 may include a tapered body 722 that may be similar in function to the tapered body 712 shown in Figure 7A, providing sealing and thermal expansion accommodation within the extrusion press system. The mandrel 720 may feature an interface surface 723 that may include protruding structures configured in a cross-spade with 45° spades arrangement. The interface surface 723 may include cross arms 724 that may have elongated triangle cross-sections, where the tips of the triangle cross-sections may form a cross shape that interfaces with the billet material. The cross arms 724 may extend radially from the center of the interface surface 723 and may provide primary contact points for force transmission between the mandrel 720 and the billet.

[0073] The mandrel 720 may also include spade arms 726 that may be positioned at 45° angles relative to the cross arms 724. Each spade arm 726 may have a triangle crosssection configuration where the tips of the triangles may merge at the center of the protruding structure on the interface surface 723. The spade arms 726 may provide additional contact points with the billet material and may increase the total interfacial area available for torque transmission. The combination of the cross arms 724 and the spade arms 726 may create a more complex surface topology that may engage with the billet material at multiple angles and orientations. In some cases, this multi-directional engagement may enhance the ability of the mandrel 720 to transmit rotational forces to the billet while preventing slipping between the mandrel and the billet interface. The mandrel 720 may include rounded corners 725 at the intersections between the protruding structures and the interface surface 723, which may facilitate insertion and retraction operations similar to the rounded corners 715 described in connection with Figure 7A.

[0074] The cross-spade surface configurations shown in Figures 7A and 7B may provide enhanced torque transmission capabilities compared to conventional smooth interface surfaces. The protruding structures may penetrate into the softened billet material and may create mechanical interlocking between the dummy block assembly and the billet. In some cases, the increased interfacial area created by the protruding arms and spade arms may distribute the transmitted forces over a larger contact area, which may reduce the likelihood of material failure or slipping at the interface. The triangle cross-section profiles of the protruding structures may create sharp edges that can effectively engage with the billet material while the rounded corners may prevent damage to the billet or dummy block during engagement and disengagement operations. The specialized surface configurations may enable the dummy block assemblies to handlethe higher torques and forces associated with commercial scale shear assisted extrusion processes while maintaining reliable force transmission throughout the extrusion cycle.

[0075] Referring to Figure 7C, alternative surface configurations may provide enhanced engagement characteristics through curved geometries that may conform to the deformation patterns of softened billet materials. The mandrel 730 may include a tapered body 732 that may be configured to fit within the expansion ring 2 and may provide sealing functionality during shear assisted extrusion operations. The tapered body 732 may accommodate thermal expansion during preheating while maintaining proper clearances within the container system. A surface 733 may be positioned at the billet interface end of the mandrel and may be configured to contact and engage with the billet material during the extrusion process. The surface 733 may include a plurality of protruding structures that may extend from the base surface to create mechanical engagement with the softened billet material.

[0076] The protruding structures on the surface 733 may comprise an arced crossspade configuration where each structural element may have a curved geometry that may follow the natural flow patterns of the deforming billet material. An arced arm 734 may extend from the surface 733 and may have a curved profile that may distribute contact forces over a broader area compared to straight-edged configurations. The arced arm 734 may be shaped to follow the rotational motion indicated by the rotation direction, which may enhance the coupling between the mandrel and the billet during rotational movement. In some cases, the curved geometry of the arced arm 734 may reduce stress concentrations that might occur with sharp-edged protruding structures while maintaining effective penetration into the softened billet material. The arced configuration may allow the protruding structures to engage with the billet material in a manner that may accommodate the complex deformation patterns that occur during shear assisted extrusion processes. A rounded corner 735 may be positioned where the arced arm 734intersects with the surface 733, and the rounded corner 735 may facilitate smooth engagement and disengagement of the dummy block assembly with the billet material during insertion and retraction operations.

[0077] With reference to Figure 7D, further variations in surface geometry may incorporate serpentine configurations that may provide enhanced mechanical interlocking with billet materials under high-temperature and high-deformation conditions. The mandrel 740 may include a tapered body 742 that may function similarly to the tapered body 732 shown in Figure 7C, providing accommodation for thermal expansion and sealing within the container system. A surface 743 may be configured at the billet interface end of the mandrel and may include protruding structures designed to engage with the billet material during shear assisted extrusion operations.

[0078] The surface 743 may include protruding arms 744 that may be configured in an S blend cross-spade arrangement where each structural element may have a serpentine or S-shaped profile. The protruding arms 744 may extend from the surface 743 and may follow curved paths that may create multiple contact points with the billet material as the dummy block assembly rotates in the direction indicated by the directional arrows 740. The S-shaped geometry of the protruding arms 744 may provide enhanced mechanical engagement compared to straight or simply curved configurations by creating a more complex interface topology that may resist slipping between the dummy block assembly and billet. In some cases, the serpentine profile of the protruding arms 744 may allow the structures to maintain contact with the billet material throughout the rotational cycle, which may ensure consistent torque transmission during the extrusion process. The S blend cross-spade configuration may distribute the transmitted forces across multiple contact surfaces, which may reduce the likelihood of localized material failure or interface slipping under the high torques associated with commercial scale shear assisted extrusion operations. Rounded corners 745 may be positioned at the intersectionsbetween the protruding arms 744 and the surface 743, and the rounded corners 745 may facilitate insertion and retraction operations while reducing stress concentrations that might otherwise compromise the structural integrity of the dummy block assembly or cause damage to the billet material during engagement and disengagement cycles.

[0079] Referring to Figure 7E, spreader surface configurations may provide alternative approaches to torque transmission through centralized force distribution patterns that may concentrate contact forces at the center of the billet interface. A mandrel 750 may include a stem connector 751 that may be configured to connect with the holder 1 of the dummy block system and may provide mechanical coupling for both axial and rotational force transmission from the pressing stem. The stem connector 751 may be designed to withstand the combined loading conditions encountered during shear assisted extrusion operations while maintaining proper alignment with the pressing stem assembly. The mandrel 750 may also include a tapered body 752 that may transition from a larger diameter at the billet interface end to a smaller diameter at the stem connector 751. The tapered body 752 may be configured to fit within the expansion ring 2 and may provide sealing functionality during extrusion operations while accommodating thermal expansion that occurs during preheating of the dummy block components.

[0080] The mandrel 750 may feature an interface surface 753 that may be configured to engage with the billet material during shear assisted extrusion processes. The interface surface 753 may include a plurality of protruding structures arranged in a spreader dished configuration where the structural elements may be designed to concentrate forces toward the center of the billet interface. In some cases, the protruding structures may comprise a protruding arm 754 that may have a triangle cross-section shape where the triangular profile may create pointed edges that can penetrate into the preheated billet material. The protruding arm 754 may extend radially from the interface surface 753 and may be oriented such that the tips of the triangular cross-sections may merge at the centerof the interface surface 753. This centralized convergence of the protruding arm 754 may create a unified contact point that may distribute rotational forces from the center of the billet interface outward through the billet material. The triangle cross-section configuration of the protruding arm 754 may provide sharp engagement edges that can effectively penetrate the softened billet material while maintaining structural integrity under the high forces and temperatures encountered during commercial scale shear assisted extrusion operations.

[0081] The protruding arm 754 may include a rounded corner 755 where the triangular structure intersects with the interface surface 753. The rounded corner 755 may facilitate the insertion of the mandrel 750 into the billet material during engagement operations and may also aid in the retraction of the mandrel 750 from the billet after the extrusion process may be completed. In some cases, the rounded corner 755 may reduce stress concentrations that might otherwise occur at sharp transitions between the protruding arm 754 and the interface surface 753, which may help maintain the structural integrity of both the mandrel 750 and the billet material during high-force operations. The spreader dished configuration may maximize the interfacial contact area between the billet and the mandrel 750 by creating multiple penetration points that converge toward the center of the interface, which may ensure effective torque transfer and rotation of the billet material throughout the extrusion process. The centralized force distribution pattern created by the converging triangular arms may provide enhanced mechanical coupling compared to distributed surface configurations, particularly under the high torque conditions associated with commercial scale shear assisted extrusion processes.

[0082] With reference to Figure 7F, alternative spreader configurations may incorporate curved surface geometries that may provide enhanced conformance to the deformation characteristics of softened billet materials under rotational loading conditions. The mandrel 760 may include a tapered body 762 that may function similarlyto the tapered body 752 shown in Figure 7E, providing accommodation for thermal expansion and sealing within the container system during shear assisted extrusion operations. A surface 763 may be positioned at the billet interface end of the mandrel and may be configured to contact and engage with the billet material during the extrusion process. The surface 763 may include a plurality of protruding structures that may extend from the base surface to create mechanical engagement with the softened billet material through curved contact geometries.

[0083] The protruding structures on the surface 763 may comprise a spreader domed configuration where each structural element may have a curved dome geometry that may distribute contact forces over a broader surface area compared to sharp-edged configurations. Protruding arms 764 may extend from the surface 763 and may form domed surfaces that may follow the natural deformation patterns of the billet material. The domed surface configuration of the protruding arms 764 may provide enhanced contact area with the billet material while reducing stress concentrations that might occur with sharp-edged protruding structures. In some cases, the curved dome geometry may allow the protruding arms 764 to maintain consistent contact with the billet material throughout the rotational cycle, which may ensure continuous torque transmission during the extrusion process. The spreader domed arrangement may create a surface topology that may accommodate the complex flow patterns of the softened billet material while providing multiple contact points for force transmission between the dummy block assembly and the billet.

[0084] The protruding arms 764 may include rounded corners 765 where the domed structures intersect with the surface 763. The rounded comers 765 may facilitate smooth engagement and disengagement of the mandrel with the billet material during insertion and retraction operations, which may reduce the likelihood of damage to either the dummy block assembly or the billet during these critical phases of the extrusion cycle. Insome cases, the rounded corners 765 may help distribute the contact stresses that occur during initial engagement of the mandrel with the billet material, which may prevent localized material failure or surface damage that could compromise the effectiveness of the torque transmission interface. The combination of the domed surface geometry of the protruding arms 764 and the rounded corners 765 may create a surface configuration that may maximize the interfacial contact area between the mandrel and the billet while providing smooth engagement characteristics that may facilitate reliable operation under the demanding conditions of commercial scale shear assisted extrusion processes. The spreader domed configuration may provide enhanced mechanical coupling compared to conventional smooth interface surfaces while maintaining the structural integrity and operational reliability needed for high-volume production applications.

[0085] Referring to Figure 7G, cone-based surface configurations may provide alternative approaches to billet engagement through discrete penetration points that may be distributed across the interface surface to create multiple contact zones for torque transmission. The mandrel 770 may have an interface surface 773 that may comprise a plurality of protruding cones 774 that may extend from the base surface and may be arranged in a pattern across the interface area to provide distributed contact points with the billet material. Each protruding cone 774 may have a generally conical geometry with a slightly flattened top surface that may provide a contact area for engaging with the softened billet material. The slightly flat top configuration of each protruding cone 774 may create a contact surface that can penetrate into the billet material while distributing the contact stresses over a finite area rather than concentrating forces at a single point. In some cases, the protruding cone 774 may be designed with specific height and diameter dimensions that optimize the penetration depth into the softened billet material while maintaining structural integrity under the high forces encountered during commercial scale shear assisted extrusion operations. The conical geometry of theprotruding cone 774 may facilitate insertion into the billet material during engagement while the flattened top surface may provide a stable contact interface for torque transmission throughout the extrusion cycle.

[0086] The protruding cone 774 may include a rounded corner 775 where the conical structure intersects with the protruding surface 773. The rounded comer 775 may facilitate smooth engagement and disengagement of the mandrel 770 with the billet material during insertion and retraction operations, which may reduce the likelihood of damage to either the dummy block components or the billet material during these operational phases. In some cases, the rounded corner 775 may help distribute the contact stresses that occur during initial engagement of the protruding cone 774 with the billet material, which may prevent localized material failure or surface damage that could compromise the effectiveness of the torque transmission interface. The rounded transition provided by the rounded corner 775 may also reduce stress concentrations that might otherwise occur at sharp transitions between the protruding cone 774 and the protruding surface 773, which may help maintain the structural integrity of the mandrel body 772 under repeated loading cycles. The combination of the conical geometry and the rounded comer 775 may create a surface configuration that provides effective billet penetration while maintaining smooth operational characteristics during engagement and retraction phases of the extrusion process.

[0087] The arrangement of multiple protruding cones 774 across the protruding surface 773 may create a distributed contact pattern that may engage with the billet material at multiple discrete points rather than through continuous surface contact. This discrete contact approach may provide enhanced mechanical interlocking between the mandrel body 772 and the billet material by creating multiple penetration points that can resist slipping during rotational loading. In some cases, the spacing and arrangement of the protruding cones 774 may be optimized to provide maximum interfacial contact areawhile ensuring that each individual protruding cone 774 can effectively penetrate the softened billet material without interference from adjacent structures. The cone-based surface configuration may accommodate variations in billet material properties and temperature conditions by providing multiple independent contact points that can adapt to local variations in material softness or deformation characteristics. The slightly flat top surfaces of the protruding cones 774 may ensure that each contact point provides a stable interface for torque transmission while the overall pattern of protruding cones 774 may distribute the transmitted forces across the entire billet interface area, which may enhance the reliability and effectiveness of the torque transmission system under the demanding conditions of commercial scale shear assisted extrusion processes.

[0088] Material selection for dummy block assemblies may play a role in ensuring reliable operation under the demanding conditions encountered during commercial scale shear assisted extrusion processes. The dummy block components may be subjected to high temperatures, substantial mechanical forces, and repeated thermal cycling that can affect the structural integrity and dimensional stability of the materials. In some cases, the material composition may need to accommodate both the elevated temperatures that occur during billet preheating operations and the high contact stresses that develop at the interface between the dummy block and the softened billet material. The selection of appropriate materials may also consider the wear resistance characteristics needed to maintain surface integrity of the protruding structures and interface surfaces throughout multiple extrusion cycles. Material properties such as thermal conductivity, coefficient of thermal expansion, and high-temperature strength retention may influence the performance of dummy block assemblies during extended operation under commercial production conditions.

[0089] Steel compositions may provide suitable material characteristics for dummy block construction due to their combination of strength, toughness, and thermal stabilityunder elevated temperature conditions. Steel materials may offer the mechanical properties needed to withstand the axial and rotational forces transmitted through dummy block assemblies during shear assisted extrusion operations while maintaining dimensional stability under thermal cycling conditions. In some cases, steel compositions may be selected based on their ability to retain strength and hardness at the operating temperatures encountered during extrusion processes, which may range from ambient conditions during assembly operations to elevated temperatures during billet preheating and extrusion phases. The microstructural characteristics of steel materials may provide resistance to thermal fatigue and mechanical wear that can occur at the interface surfaces where the dummy block contacts the billet material. Steel compositions may also offer manufacturing advantages through established machining and heat treatment processes that can be used to achieve the precise dimensional tolerances and surface finishes required for effective dummy block operation.

[0090] Carbon steel compositions may be utilized for dummy block construction in applications where the combination of strength, machinability, and cost effectiveness may be appropriate for the operational requirements. Carbon steel materials may provide adequate mechanical properties for transmitting the forces and torques associated with shear assisted extrusion while offering manufacturing advantages through conventional machining and fabrication processes. In some cases, carbon steel compositions may be selected based on their carbon content levels that provide the desired balance between strength and toughness characteristics needed for dummy block applications. The heat treatment response of carbon steel materials may allow for optimization of mechanical properties through processes such as quenching and tempering that can enhance the strength and wear resistance of the finished components. Carbon steel compositions may also provide thermal stability characteristics that can accommodate the temperatureranges encountered during extrusion operations while maintaining structural integrity under repeated thermal cycling conditions.

[0091] Alloy steel compositions may offer enhanced material properties compared to carbon steel through the incorporation of alloying elements that can improve high- temperature performance, wear resistance, and mechanical strength characteristics. Alloy steel materials may include elements such as chromium, molybdenum, vanadium, or tungsten that can enhance the high-temperature strength retention and thermal stability of the dummy block components during extended operation under commercial extrusion conditions. In some cases, alloy steel compositions may be selected to provide improved hardenability characteristics that allow for more uniform mechanical properties throughout the cross-section of larger dummy block components. The alloying elements may also contribute to improved wear resistance at the interface surfaces where the dummy block contacts the billet material, which may extend the operational life of the components under the abrasive conditions that can occur during high-volume production operations. Alloy steel materials may offer enhanced thermal fatigue resistance compared to carbon steel compositions, which may be beneficial for dummy block applications that involve repeated heating and cooling cycles during commercial scale extrusion processes.

[0092] Tool steel compositions may provide specialized material characteristics that may be particularly suitable for dummy block applications requiring high wear resistance, dimensional stability, and retention of mechanical properties at elevated temperatures. Tool steel materials may be formulated with alloying elements and carbon contents that optimize the combination of hardness, toughness, and thermal stability needed for demanding manufacturing applications. In some cases, tool steel compositions may offer superior wear resistance characteristics compared to carbon steel or general alloy steel materials, which may be beneficial for maintaining the dimensional accuracy and surface integrity of protruding structures and interface surfaces throughout extended productionruns. The heat treatment response of tool steel materials may allow for precise control of mechanical properties through processes that can optimize the hardness and toughness characteristics for specific dummy block applications. Tool steel compositions may also provide enhanced thermal shock resistance that can accommodate the rapid temperature changes that may occur during the engagement and disengagement phases of the extrusion cycle.

[0093] Cold-work tool steel compositions may be designed to provide exceptional wear resistance and dimensional stability under conditions involving high contact stresses and abrasive wear mechanisms. Cold-work tool steel materials may incorporate high carbon contents and alloying elements such as chromium, molybdenum, and vanadium that contribute to the formation of hard carbide phases that enhance wear resistance characteristics. In some cases, cold-work tool steel compositions may be selected for dummy block applications where the interface surfaces may be subjected to severe abrasive conditions during contact with billet materials that contain hard particles or abrasive constituents. The microstructural characteristics of cold-work tool steel materials may provide resistance to surface deformation and wear that can occur under the high contact pressures developed at the dummy block and billet interface during force transmission operations. Cold-work tool steel compositions may also offer excellent dimensional stability characteristics that can maintain the precise geometric relationships of protruding structures and interface surfaces throughout multiple extrusion cycles under varying thermal and mechanical loading conditions.

[0094] Hot-work tool steel compositions may be specifically formulated to provide optimal performance characteristics under the elevated temperature conditions encountered during shear assisted extrusion processes. Hot-work tool steel materials may incorporate alloying elements such as chromium, molybdenum, tungsten, and vanadium that enhance high-temperature strength retention, thermal fatigue resistance,and oxidation resistance characteristics. In some cases, hot-work tool steel compositions may be selected for dummy block applications where the components may be subjected to sustained elevated temperatures during billet preheating operations and extrusion processes. The thermal stability characteristics of hot-work tool steel materials may allow the dummy block components to maintain their mechanical properties and dimensional accuracy under the temperature cycling conditions that occur during commercial scale extrusion operations. Hot-work tool steel compositions may also provide enhanced resistance to thermal shock and thermal fatigue that can result from the rapid temperature changes that occur during the engagement and disengagement phases of the extrusion cycle, which may contribute to extended operational life under demanding production conditions.

[0095] High-speed steel compositions may offer advanced material characteristics that combine high-temperature performance with exceptional wear resistance and cutting edge retention properties that may be beneficial for specialized dummy block applications. High-speed steel materials may incorporate complex alloying systems that include elements such as tungsten, molybdenum, chromium, vanadium, and cobalt that contribute to the formation of stable carbide phases and enhanced high-temperature strength characteristics. In some cases, high-speed steel compositions may be selected for dummy block applications where the interface surfaces may be subjected to particularly severe wear conditions or where extended operational life may be required under high-volume production conditions. The metallurgical characteristics of high-speed steel materials may provide superior retention of hardness and strength at elevated temperatures compared to other steel compositions, which may be advantageous for maintaining the effectiveness of protruding structures and interface geometries throughout extended production runs. High-speed steel compositions may also offer enhanced thermal stability and resistance to softening under sustained elevatedtemperature exposure, which may contribute to consistent performance characteristics during commercial scale shear assisted extrusion operations.

[0096] The material properties that enable effective operation of dummy block assemblies under high torque and temperature conditions may include a combination of mechanical, thermal, and metallurgical characteristics that work together to provide reliable performance throughout the extrusion process. High-temperature strength retention may be a material property that allows dummy block components to maintain their load-carrying capacity and structural integrity when subjected to the elevated temperatures that occur during billet preheating and extrusion operations. In some cases, materials with good high-temperature strength retention may resist softening and deformation under the combined effects of temperature and mechanical loading, which may be necessary for maintaining the dimensional accuracy of protruding structures and interface surfaces during force transmission operations. The ability to retain strength at elevated temperatures may also contribute to the prevention of permanent deformation that could accumulate over multiple extrusion cycles and potentially compromise the effectiveness of the torque transmission interface. Materials with superior high- temperature strength characteristics may enable dummy block assemblies to operate reliably under the demanding conditions of commercial scale shear assisted extrusion while maintaining consistent performance throughout extended production runs.

[0097] Thermal stability characteristics may enable dummy block materials to accommodate the temperature variations and thermal cycling conditions encountered during shear assisted extrusion processes without experiencing detrimental microstructural changes or dimensional instability. Materials with good thermal stability may resist phase transformations, grain growth, or other metallurgical changes that could affect the mechanical properties or dimensional accuracy of the dummy block components during repeated heating and cooling cycles. In some cases, thermal stabilitymay be particularly important for maintaining the precise geometric relationships of protruding structures and interface surfaces that are necessary for effective torque transmission between the dummy block and billet material. The thermal expansion characteristics of dummy block materials may also contribute to operational effectiveness by providing predictable dimensional changes that can be accommodated within the clearance relationships of the extrusion system. Materials with appropriate thermal expansion coefficients may maintain proper sealing and engagement characteristics throughout the temperature range of the extrusion process while avoiding excessive thermal stresses that could lead to component failure or dimensional distortion.

[0098] Wear resistance properties may enable dummy block materials to maintain surface integrity and dimensional accuracy under the abrasive and adhesive wear conditions that can occur at the interface between the dummy block and billet material. Materials with good wear resistance characteristics may resist surface degradation, material transfer, and dimensional changes that could result from the sliding and contact conditions that occur during the engagement and disengagement phases of the extrusion cycle. In some cases, wear resistance may be particularly important for maintaining the effectiveness of protruding structures and interface geometries that provide the mechanical interlocking necessary for torque transmission during shear assisted extrusion operations. The hardness characteristics of dummy block materials may contribute to wear resistance by providing resistance to surface deformation and material removal under the high contact stresses that develop during force transmission operations. Materials with appropriate hardness levels may balance the need for wear resistance with the toughness characteristics necessary to resist fracture or chipping under impact loading conditions that can occur during the dynamic phases of the extrusion process.

[0099] Toughness and fracture resistance characteristics may enable dummy block materials to withstand the impact loading and stress concentrations that can occur during the engagement and disengagement operations of shear assisted extrusion processes. Materials with good toughness properties may resist crack initiation and propagation under the combined effects of mechanical loading, thermal stresses, and stress concentrations that can develop at geometric transitions and interface surfaces. In some cases, toughness characteristics may be particularly important for protruding structures and interface geometries that may be subjected to localized stress concentrations during penetration into billet materials or during separation operations after extrusion completion. The ability to resist brittle fracture may enable dummy block components to maintain structural integrity under the shock loading conditions that can occur during rapid engagement or disengagement operations, particularly when thermal expansion or material property variations may create unexpected loading conditions. Materials with balanced toughness and strength characteristics may provide the combination of loadcarrying capacity and damage tolerance necessary for reliable operation under the variable conditions encountered during commercial scale shear assisted extrusion processes.

[0100] Commercial scale shear assisted extrusion processes may involve substantially higher torque transmission requirements compared to laboratory scale operations, with dummy block assemblies potentially needing to transmit torques of 20 MN or greater from the ram to the billet material. The scaling from laboratory to commercial production may introduce torque requirements that exceed the capabilities of conventional dummy block designs by more than an order of magnitude. In some cases, the torque transmission capabilities may need to accommodate the rotational forces associated with processing billets having diameters of 7 inches or greater, where the increased cross-sectional area and material volume may create proportionally higherresistance to rotational deformation. The specialized surface configurations incorporated into dummy block assemblies may enable effective torque transmission under these demanding conditions by providing enhanced mechanical coupling between the dummy block and billet material through increased interfacial contact area and improved penetration characteristics.

[0101] The torque transmission capabilities of dummy block assemblies may be enhanced through the implementation of protruding surface structures that create multiple contact points and mechanical interlocking mechanisms with the softened billet material. The protruding structures may penetrate into the preheated billet material to establish mechanical engagement that can resist the rotational forces encountered during commercial scale extrusion operations. In some cases, the depth of penetration and the contact area provided by the protruding structures may be proportioned to accommodate the torque levels associated with processing large diameter billets where the material resistance to rotation may increase substantially compared to smaller diameter applications. The geometric configuration of the protruding structures may distribute the transmitted torque across multiple contact zones, which may reduce the likelihood of localized material failure or slipping at the dummy block and billet interface under high torque conditions.

[0102] The interfacial contact area between the dummy block and billet material may play a role in determining the maximum torque transmission capability of the system by providing the surface area over which the rotational forces may be distributed. Dummy block assemblies with specialized surface configurations may provide substantially increased interfacial contact area compared to conventional smooth interface designs, which may enable the transmission of higher torques without exceeding the shear strength of the billet material at the interface. In some cases, the increased contact area may be achieved through the incorporation of multiple protruding structures that creatediscrete contact zones distributed across the billet interface surface. The total effective contact area may be the sum of the individual contact areas provided by each protruding structure, which may result in a cumulative contact area that substantially exceeds the geometric area of the interface surface. The enhanced contact area may enable the dummy block assembly to transmit the high torques associated with commercial scale operations while maintaining contact stresses within acceptable limits for the billet material properties.

[0103] The mechanical interlocking characteristics provided by protruding surface structures may contribute to torque transmission capabilities by creating engagement mechanisms that resist relative motion between the dummy block and billet material during rotational loading. The protruding structures may create mechanical keys or anchors that penetrate into the softened billet material and provide resistance to rotational slipping through geometric interference rather than relying solely on frictional forces at the interface. In some cases, the mechanical interlocking may be enhanced by the specific geometric configurations of the protruding structures, such as cross-spade arrangements, cone patterns, or other surface topologies that create multiple engagement points with different orientational characteristics. The interlocking mechanisms may accommodate the complex stress distributions that occur during high torque transmission by providing multiple load paths through which the rotational forces may be transferred from the dummy block to the billet material. The geometric interference provided by the protruding structures may maintain effective torque transmission even under conditions where thermal expansion, material property variations, or other factors might otherwise compromise the effectiveness of purely frictional coupling mechanisms.

[0104] The torque transmission capabilities of dummy block assemblies may be affected by the material properties and temperature conditions of the billet material duringthe extrusion process. The preheated billet material may have reduced yield strength and increased deformability compared to ambient temperature conditions, which may affect the maximum torque that can be transmitted through the interface without causing material failure or excessive deformation. In some cases, the softened state of the preheated billet material may facilitate the penetration of protruding structures into the billet surface, which may enhance the mechanical coupling between the dummy block and billet. The temperature-dependent material properties may also affect the contact stresses that develop at the interface during torque transmission, with higher temperatures potentially reducing the contact pressures needed to achieve effective mechanical engagement. The dummy block design may accommodate these temperature-dependent characteristics by providing protruding structures with geometric configurations that can maintain effective engagement across the range of billet temperatures encountered during commercial scale extrusion operations.

[0105] The generation of high shear strains from the rear of the billet may contribute to the overall effectiveness of the shear assisted extrusion process by creating a second region of high shear deformation in addition to the primary shear zone that occurs at the front of the billet and extrusion die face. The specialized surface configurations of dummy block assemblies may induce localized shear deformation in the billet material at the dummy block interface, which may enhance the microstructural refinement and material property improvements associated with shear assisted extrusion processes. In some cases, the protruding structures may create complex stress and strain fields in the billet material that extend beyond the immediate contact area, potentially affecting the deformation characteristics throughout a substantial portion of the billet volume. The rear shear zone created by the dummy block interface may work in conjunction with the front shear zone at the die face to provide enhanced material processing compared toconventional extrusion processes that rely primarily on the deformation that occurs at the die interface.

[0106] The dual shear zone configuration created by specialized dummy block designs may provide enhanced material mixing and homogenization throughout the billet volume during the extrusion process. The shear strains generated at the rear of the billet may create material flow patterns that promote the redistribution of alloying elements, the breakup of intermetallic compounds, and the refinement of microstructural features throughout the processed material. In some cases, the rear shear zone may be particularly effective for processing recycled or scrap materials that contain heterogeneous microstructures or compositional variations that benefit from enhanced mixing during the extrusion process. The combination of rear and front shear zones may create a more uniform deformation field throughout the billet compared to conventional extrusion processes, which may result in more consistent material properties and microstructural characteristics in the finished extruded product. The enhanced shear deformation may also contribute to improved mechanical properties and performance characteristics of the extruded material through the grain refinement and intermetallic dispersion effects associated with severe plastic deformation processes.

[0107] The torque transmission requirements for commercial scale shear assisted extrusion may vary depending on the specific material composition, billet dimensions, processing temperatures, and extrusion parameters used during the operation. Aluminum alloys with different compositions may exhibit varying resistance to rotational deformation based on their alloying elements, microstructural characteristics, and temperaturedependent flow properties. In some cases, billets containing higher levels of alloying elements or intermetallic compounds may require higher torques to achieve effective rotation and shear deformation compared to simpler alloy compositions. The billet diameter may have a substantial effect on torque requirements, with larger diameterbillets potentially requiring exponentially higher torques due to the increased moment arm and material volume that must be rotated during the extrusion process. The processing temperature may also affect torque requirements, with higher temperatures generally reducing the material flow stress and the torque needed to achieve rotation, while lower temperatures may increase the torque requirements but potentially provide enhanced microstructural refinement effects.

[0108] The operational reliability of high torque transmission systems may depend on the ability of dummy block assemblies to maintain consistent performance characteristics throughout multiple extrusion cycles under commercial production conditions. The repeated application of high torques and the thermal cycling associated with commercial scale operations may create wear and fatigue conditions that could affect the long-term effectiveness of the torque transmission interface. In some cases, the protruding structures and interface surfaces may be subjected to gradual wear that could reduce the contact area and mechanical interlocking effectiveness over extended operation periods. The material selection and heat treatment of dummy block components may contribute to operational reliability by providing resistance to wear, thermal fatigue, and dimensional changes that could compromise torque transmission capabilities. The design of protruding structures may also consider the wear characteristics and may incorporate features such as rounded corners and appropriate surface finishes that can maintain effective engagement characteristics while minimizing wear rates under high torque operating conditions.

[0109] Dummy block assemblies for shear assisted extrusion processes may be configured to accommodate a wide range of billet materials and material forms that may be encountered in commercial scale production operations. The material compatibility characteristics of dummy block systems may enable the processing of various metallic compositions while maintaining effective torque transmission and force distributioncapabilities throughout the extrusion cycle. In some cases, the specialized surface configurations and mechanical engagement features of dummy block assemblies may provide enhanced coupling effectiveness with different billet materials that exhibit varying thermal properties, mechanical characteristics, and deformation behaviors under elevated temperature conditions. The ability to process diverse material compositions may contribute to the versatility of shear assisted extrusion systems for applications involving both primary metal production and recycling operations where material composition variability may be encountered.

[0110] Aluminum-based billet materials may represent a primary category of feedstock materials that may be processed using specialized dummy block assemblies in shear assisted extrusion operations. Aluminum billets may provide favorable processing characteristics due to the relatively low melting temperature and good deformability of aluminum under elevated temperature conditions. In some cases, aluminum billets may be preheated to temperatures that reduce the material yield strength and enhance the penetration characteristics of protruding structures on dummy block interface surfaces. The thermal conductivity properties of aluminum may facilitate uniform temperature distribution throughout the billet volume during preheating operations, which may contribute to consistent material properties and deformation behavior during the extrusion process. The lightweight characteristics of aluminum billets may also provide handling advantages during loading and positioning operations in commercial scale extrusion systems while maintaining the structural integrity needed for effective force transmission during high torque operations.

[0111] Iron-containing billet materials may be processed using dummy block assemblies configured to accommodate the higher strength and temperature requirements associated with ferrous metal compositions. Iron billets may require higher processing temperatures compared to aluminum materials to achieve the softened stateneeded for effective penetration of protruding structures and mechanical coupling with dummy block interface surfaces. In some cases, the higher strength characteristics of iron materials may provide enhanced resistance to deformation at the dummy block interface, which may require protruding structures with increased penetration depth or enhanced geometric configurations to achieve effective torque transmission. The thermal expansion characteristics of iron billets may differ from aluminum materials, which may affect the clearance relationships and sealing characteristics of dummy block assemblies during thermal cycling operations. The magnetic properties of iron materials may also provide opportunities for specialized handling and positioning systems that could enhance the efficiency of billet loading and alignment operations in commercial scale extrusion systems.

[0112] Copper-containing billet materials may offer processing characteristics that combine good thermal conductivity with enhanced electrical properties that may be beneficial for specialized extrusion applications. Copper billets may exhibit favorable deformation characteristics under elevated temperature conditions, which may facilitate the penetration of protruding structures and the establishment of effective mechanical coupling with dummy block interface surfaces. In some cases, the high thermal conductivity of copper materials may require adjusted preheating procedures to achieve uniform temperature distribution throughout the billet volume while avoiding excessive heat loss during handling and positioning operations. The corrosion resistance characteristics of copper materials may provide advantages for applications involving exposure to aggressive environments or extended storage periods between processing operations. The density characteristics of copper billets may affect the handling requirements and equipment specifications for commercial scale extrusion systems while providing enhanced material properties in the finished extruded products.

[0113] Silicon-containing billet materials may be incorporated into extrusion operations to provide enhanced wear resistance and specialized mechanical properties in the finished extruded products. Silicon additions to billet compositions may affect the deformation characteristics and temperature-dependent flow properties of the material during shear assisted extrusion processes. In some cases, silicon-containing billets may exhibit increased hardness characteristics that could affect the penetration depth and engagement effectiveness of protruding structures on dummy block interface surfaces. The thermal expansion characteristics of silicon-containing materials may differ from pure metal compositions, which may require adjustments to the clearance relationships and dimensional tolerances of dummy block assemblies to maintain effective sealing and engagement characteristics throughout the temperature range of the extrusion process. The abrasive characteristics of silicon-containing materials may also affect the wear rates and operational life of dummy block components, particularly at the interface surfaces where mechanical coupling occurs during torque transmission operations.

[0114] Magnesium-containing billet materials may provide lightweight characteristics combined with good strength-to-weight ratios that may be beneficial for specialized extrusion applications. Magnesium billets may exhibit favorable deformation characteristics under elevated temperature conditions, which may facilitate effective mechanical coupling with dummy block interface surfaces during shear assisted extrusion operations. In some cases, the low density characteristics of magnesium materials may affect the handling procedures and equipment requirements for commercial scale extrusion systems while providing weight reduction benefits in the finished extruded products. The thermal properties of magnesium billets may require specialized preheating procedures to achieve uniform temperature distribution while avoiding excessive oxidation or other thermal degradation effects that could compromise material quality. The reactivity characteristics of magnesium materials may also require specializedatmospheric control or protective measures during processing operations to maintain material integrity and prevent contamination that could affect the performance of the finished extruded products.

[0115] Manganese-containing billet materials may be processed to provide enhanced strength characteristics and improved corrosion resistance in the finished extruded products. Manganese additions to billet compositions may affect the deformation behavior and temperature-dependent flow properties during shear assisted extrusion processes. In some cases, manganese-containing billets may exhibit increased strength characteristics that could require higher torque transmission capabilities from dummy block assemblies to achieve effective rotation and shear deformation during the extrusion process. The work hardening characteristics of manganese-containing materials may affect the penetration depth and engagement effectiveness of protruding structures on dummy block interface surfaces, particularly under the high strain conditions that occur during commercial scale extrusion operations. The thermal stability characteristics of manganese-containing billets may provide advantages for applications involving elevated temperature exposure or thermal cycling conditions while maintaining consistent material properties throughout the extrusion process.

[0116] Zinc-containing billet materials may offer processing advantages through reduced melting temperatures and enhanced deformability characteristics that may facilitate effective mechanical coupling with dummy block assemblies. Zinc billets may exhibit favorable flow properties under elevated temperature conditions, which may enhance the penetration characteristics of protruding structures and improve the effectiveness of torque transmission during shear assisted extrusion operations. In some cases, the low melting temperature of zinc materials may require careful temperature control during preheating operations to achieve the desired softened state while avoiding excessive material degradation or dimensional changes that could affect the engagementcharacteristics with dummy block interface surfaces. The corrosion resistance properties of zinc materials may provide protective benefits for applications involving exposure to aggressive environments while maintaining the structural integrity needed for effective force transmission during high torque operations. The density characteristics of zinc billets may affect the handling requirements and equipment specifications for commercial scale extrusion systems while providing enhanced material properties in specialized applications.

[0117] Aluminum alloy compositions may represent a major category of billet materials that may be processed using specialized dummy block assemblies in commercial scale shear assisted extrusion operations. Aluminum alloys may combine the favorable processing characteristics of pure aluminum with enhanced mechanical properties and specialized performance characteristics provided by alloying elements. In some cases, aluminum alloy billets may be formulated to provide specific combinations of strength, corrosion resistance, thermal properties, and deformability characteristics that may be optimized for particular extrusion applications. The alloying elements in aluminum compositions may affect the temperature-dependent flow properties and deformation behavior during shear assisted extrusion processes, which may influence the torque transmission requirements and the effectiveness of mechanical coupling with dummy block interface surfaces. The microstructural characteristics of aluminum alloys may also be affected by the shear deformation processes that occur during extrusion, potentially providing enhanced grain refinement and property improvements compared to conventional extrusion processes.

[0118] 3xxx series aluminum alloys may be processed using dummy block assemblies configured to accommodate the manganese-containing compositions that characterize this alloy family. 3xxx series aluminum alloys may provide enhanced strength characteristics compared to pure aluminum while maintaining good formabilityand corrosion resistance properties. In some cases, 3xxx series alloys may exhibit work hardening characteristics that could affect the penetration depth and engagement effectiveness of protruding structures on dummy block interface surfaces during high strain deformation processes. The manganese content in 3xxx series alloys may contribute to improved thermal stability and strength retention at elevated temperatures, which may provide advantages during the preheating and extrusion phases of the process. The deformation characteristics of 3xxx series alloys may be compatible with the torque transmission capabilities of specialized dummy block assemblies while providing enhanced material properties in the finished extruded products through the grain refinement effects associated with shear assisted extrusion processes.

[0119] 5xxx series aluminum alloys may be processed using dummy block systems designed to accommodate the magnesium-containing compositions that provide enhanced strength and corrosion resistance characteristics. 5xxx series aluminum alloys may exhibit favorable deformation properties under elevated temperature conditions, which may facilitate effective mechanical coupling with dummy block interface surfaces during shear assisted extrusion operations. In some cases, the magnesium content in 5xxx series alloys may affect the work hardening behavior and strain rate sensitivity of the material during high deformation processes, which may influence the torque transmission requirements and the effectiveness of protruding structure engagement. The corrosion resistance characteristics of 5xxx series alloys may provide advantages for applications involving marine environments or other aggressive exposure conditions while maintaining the structural integrity needed for effective force transmission during commercial scale extrusion operations. The thermal properties of 5xxx series alloys may require specialized preheating procedures to achieve uniform temperature distribution throughout the billet volume while optimizing the material flow characteristics for enhanced shear deformation effects.

[0120] 6xxx series aluminum alloys may represent a widely processed category of billet materials that may benefit from the enhanced deformation characteristics provided by shear assisted extrusion processes using specialized dummy block assemblies. 6xxx series aluminum alloys may contain both magnesium and silicon alloying elements that provide heat treatability and enhanced strength characteristics through precipitation hardening mechanisms. In some cases, 6xxx series alloys may exhibit complex deformation behavior during shear assisted extrusion due to the interaction between the applied shear strains and the precipitation characteristics of the alloy system. The silicon and magnesium content in 6xxx series alloys may affect the temperature-dependent flow properties and the effectiveness of mechanical coupling with dummy block interface surfaces during torque transmission operations. The heat treatment response of 6xxx series alloys may be enhanced by the severe deformation effects associated with shear assisted extrusion processes, potentially providing improved mechanical properties and microstructural characteristics in the finished extruded products compared to conventional extrusion processes.

[0121] 7xxx series aluminum alloys may be processed using dummy block assemblies configured to handle the higher strength characteristics and specialized deformation behavior associated with zinc-containing aluminum compositions. 7xxx series aluminum alloys may provide the highest strength characteristics among aluminum alloy families, which may require enhanced torque transmission capabilities from dummy block assemblies to achieve effective rotation and shear deformation during commercial scale extrusion operations. In some cases, the zinc and magnesium content in 7xxx series alloys may create complex precipitation behavior that could be affected by the severe deformation conditions associated with shear assisted extrusion processes. The work hardening characteristics of 7xxx series alloys may affect the penetration depth and engagement effectiveness of protruding structures on dummy block interface surfaces,particularly under the high strain rate conditions that occur during commercial scale operations. The thermal sensitivity of 7xxx series alloys may require precise temperature control during preheating and extrusion operations to optimize the material flow characteristics while avoiding overaging or other thermal effects that could compromise the mechanical properties of the finished extruded products.

[0122] Billet materials may be supplied and processed in various physical forms that may affect the handling procedures, preheating requirements, and mechanical coupling characteristics with dummy block assemblies during shear assisted extrusion operations. The physical form of the billet material may influence the temperature distribution characteristics during preheating operations and may affect the uniformity of material properties throughout the billet volume during the extrusion process. In some cases, different material forms may require specialized handling equipment or modified processing procedures to achieve effective loading and positioning within the extrusion system while maintaining the material integrity needed for reliable torque transmission during high force operations. The surface characteristics and dimensional tolerances of different material forms may also affect the sealing relationships and clearance requirements for dummy block assemblies during engagement and retraction operations throughout the extrusion cycle.

[0123] Powderform billet materials may be processed using dummy block assemblies configured to accommodate the unique handling and consolidation characteristics associated with particulate feedstock materials. Powder billets may be formed through compaction processes that create consolidated shapes suitable for extrusion operations while maintaining the material composition and property characteristics of the constituent powder particles. In some cases, powder form billets may exhibit different deformation characteristics compared to solid billets due to the presence of particle boundaries and potential porosity within the consolidated structure. The consolidation characteristics ofpowder billets may be enhanced by the severe deformation effects associated with shear assisted extrusion processes, potentially providing improved density and mechanical properties in the finished extruded products. The surface characteristics of powder form billets may affect the penetration depth and engagement effectiveness of protruding structures on dummy block interface surfaces, particularly during the initial engagement phase when the consolidated powder structure may undergo additional densification under the applied forces.

[0124] Flake form billet materials may be processed using specialized dummy block configurations that accommodate the unique geometry and consolidation requirements associated with thin, plate-like feedstock materials. Flake billets may be formed through compaction of metallic flakes that provide high surface area characteristics and potential advantages for material mixing and homogenization during shear assisted extrusion processes. In some cases, flake form billets may exhibit anisotropic deformation characteristics due to the preferred orientation of the flake particles within the consolidated structure, which may affect the torque transmission requirements and the effectiveness of mechanical coupling with dummy block interface surfaces. The consolidation behavior of flake billets may be enhanced by the rotational shear effects associated with shear assisted extrusion, potentially providing improved material density and property uniformity in the finished extruded products. The surface texture characteristics of flake form billets may provide enhanced mechanical interlocking with protruding structures on dummy block interface surfaces, which may contribute to improved torque transmission effectiveness during commercial scale extrusion operations.

[0125] Scrap form billet materials may be processed using dummy block assemblies designed to accommodate the compositional variability and heterogeneous microstructural characteristics associated with recycled metallic feedstock materials.Scrap billets may be formed from various sources of recycled metal that may contain different alloying elements, impurity levels, and microstructural features compared to primary metal feedstock materials. In some cases, scrap form billets may exhibit variable deformation characteristics throughout the billet volume due to compositional segregation or microstructural heterogeneity that may affect the uniformity of mechanical coupling with dummy block interface surfaces. The material mixing and homogenization effects associated with shear assisted extrusion processes may provide particular advantages for processing scrap form billets by reducing compositional variations and improving property uniformity in the finished extruded products. The surface characteristics of scrap form billets may vary depending on the source and preparation methods used for the recycled material, which may require dummy block assemblies with enhanced penetration capabilities or specialized surface configurations to achieve effective torque transmission during commercial scale operations.

[0126] Solid form billet materials may represent the most conventional category of feedstock materials that may be processed using specialized dummy block assemblies in shear assisted extrusion operations. Solid billets may be produced through casting, forging, or other primary forming processes that create homogeneous material structures with consistent composition and microstructural characteristics throughout the billet volume. In some cases, solid form billets may provide the most predictable deformation behavior and mechanical coupling characteristics with dummy block interface surfaces due to the uniform material properties and consistent surface characteristics. The thermal conductivity and heat transfer characteristics of solid billets may facilitate uniform temperature distribution during preheating operations, which may contribute to consistent material flow properties and effective torque transmission during the extrusion process. The surface finish and dimensional accuracy characteristics of solid form billets may provide optimal sealing and engagement relationships with dummy block assemblieswhile minimizing the clearance variations that could affect the effectiveness of force transmission during commercial scale extrusion operations.

[0127] A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure. Accordingly, other implementations are within the scope of the following claims.DOCTRINE OF EQUIVALENTS

[0128] This description of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form described, and many modifications and variations are possible in light of the teaching above. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications. This description will enable others skilled in the art to best utilize and practice the invention in various embodiments and with various modifications as are suited to a particular use. The scope of the invention is defined by the following claims.

[0129] As used herein, the singular terms "a," "an," and "the" may include plural referents unless the context clearly dictates otherwise. Reference to an object in the singular is not intended to mean "one and only one" unless explicitly so stated, but rather "one or more."

[0130] As used herein, the terms "approximately" and "about" are used to describe and account for small variations. When used in conjunction with an event or circumstance, the terms can refer to instances in which the event or circumstance occurs precisely as well as instances in which the event or circumstance occurs to a close approximation. When used in conjunction with a numerical value, the terms can refer to a range of variation of less than or equal to ± 10% of that numerical value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%,less than or equal to ±1 %, less than or equal to ±0.5%, less than or equal to ±0.1 %, or less than or equal to ±0.05%.

[0131] Additionally, amounts, ratios, and other numerical values may sometimes be presented herein in a range format. It is to be understood that such range format is used for convenience and brevity and should be understood flexibly to include numerical values explicitly specified as limits of a range, but also to include all individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly specified. For example, a ratio in the range of about 1 to about 200 should be understood to include the explicitly recited limits of about 1 and about 200, but also to include individual ratios such as about 2, about 3, and about 4, and sub-ranges such as about 10 to about 50, about 20 to about 100, and so forth.

Claims

CLAIMS1 . A dummy block for a shear assisted direct extrusion press, comprising: a mandrel comprising a first end and a second end, wherein the first end comprises a surface configured to interface with a billet; and wherein the surface comprises a plurality of structures protruding from the surface, wherein the plurality of structures are configured to protrude into the billet during a shear assisted direct extrusion process to transmit rotational torque from the dummy block to the billet.

2. The dummy block of claim 1 , wherein the mandrel has a tapered shape, wherein the first end has a larger diameter than the second end.

3. The dummy block of claim 1 , wherein the plurality of structures comprise a shape selected from the group consisting of: a cross-spade shape, a cross-spade with 45° spades shape, an arced cross-spade shape, an S blend cross-spade shape, a spreader dished shape, a spreader domed shape, and a plurality of protruding cones.

4. The dummy block of claim 3, wherein the plurality of structures comprise the crossspade shape, and wherein each structure comprises protruding arms arranged in a cross pattern with triangular cross-sections.

5. The dummy block of claim 3, wherein the plurality of structures comprise the plurality of protruding cones, and wherein each protruding cone has a generally conical geometry with a flattened top surface.

6. The dummy block of claim 1 , wherein the plurality of structures include rounded corners where the structures intersect with the surface.

7. The dummy block of claim 6, wherein the rounded corners facilitate insertion of the dummy block into the billet and retraction of the dummy block from the billet.

8. The dummy block of claim 1 , wherein the dummy block comprises a material selected from the group consisting of: steel, carbon steel, alloy steel, tool steel, hot-work tool steel, cold-work tool steel, and high-speed steel.

9. The dummy block of claim 1 , wherein the dummy block is configured to transmit a torque greater than or equal to 20 MN from a ram to the billet.

10. The dummy block of claim 1 , further comprising an inverted relief angle configured to facilitate separation of the dummy block from the billet after completion of the shear assisted direct extrusion process.11 . A shear assisted direct extrusion process, comprising: applying an axial and rotational movement to a dummy block via a ram of a shear assisted direct extrusion press, wherein the dummy block comprises a mandrel comprising a first end, wherein the first end comprises a surface configured to interface with a billet, and wherein the surface comprises a plurality of structures protruding from the surface; and extruding a part from the billet by transmitting the axial and rotational movement from the dummy block to the billet through the plurality of structures protruding into the billet.

12. The process of claim 11 , wherein the mandrel has a tapered shape, wherein the first end has a larger diameter than a second end of the mandrel.

13. The process of claim 11 , wherein the plurality of structures comprise a shape selected from the group consisting of: a cross-spade shape, a cross-spade with 45° spades shape, an arced cross-spade shape, an S blend cross-spade shape, a spreader dished shape, a spreader domed shape, and a plurality of protruding cones.

14. The process of claim 13, wherein the plurality of structures comprise the cross-spade shape, and wherein each structure comprises protruding arms arranged in a cross pattern with triangular cross-sections that merge at a center of the surface.

15. The process of claim 11 , wherein the dummy block transmits a torque greater than or equal to 20 MN from the ram to the billet, and wherein the part has a diameter greater than or equal to 7 inches.

16. A dummy block assembly for transmitting torque in a shear assisted extrusion system, comprising: a mandrel having a tapered body with a larger diameter first end and a smaller diameter second end; wherein the first end comprises an interface surface having a plurality of protruding structures extending therefrom; and wherein the plurality of protruding structures are configured to penetrate into a softened billet material to create mechanical interlocking for torque transmission during rotation of the mandrel.

17. The dummy block assembly of claim 16, wherein the plurality of protruding structures comprise a shape selected from the group consisting of: a cross-spade shape, a crossspade with 45° spades shape, an arced cross-spade shape, an S blend cross-spade shape, a spreader dished shape, a spreader domed shape, and a plurality of protruding cones.

18. The dummy block assembly of claim 17, wherein the plurality of protruding structures comprise the cross-spade shape, and wherein each protruding structure comprises protruding arms arranged in a cross pattern with triangular cross-sections that converge toward a center of the interface surface.

19. The dummy block assembly of claim 16, wherein the plurality of protruding structures include rounded corners where the protruding structures intersect with the interface surface to facilitate engagement and disengagement with the billet material.

20. The dummy block assembly of claim 19, wherein the mandrel comprises a material selected from the group consisting of: steel, carbon steel, alloy steel, tool steel, hot-work tool steel, cold-work tool steel, and high-speed steel, and wherein the dummy block assembly is configured to transmit a torque greater than or equal to 20 MN.

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