Method for regulating and controlling mechanical properties of die-casting amorphous alloy
By controlling the high shear rate in the vacuum die casting process and adjusting the injection rate to change the shear strain rate of amorphous alloys, the problem of high brittleness and poor plasticity of amorphous alloys at room temperature is solved. This achieves efficient and flexible control of mechanical properties, improving production efficiency and material properties.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SOUTH CHINA UNIV OF TECH
- Filing Date
- 2026-03-12
- Publication Date
- 2026-05-12
AI Technical Summary
Existing amorphous alloys are brittle at room temperature and lack plastic deformation ability. Existing performance control methods are costly and inefficient, making it difficult to flexibly control their 'strength-toughness' matching relationship while maintaining high strength.
By controlling the high shear rate in the vacuum die casting process to alter the shear strain rate of the amorphous alloy, the relaxation behavior of its internal structure can be controlled, thereby achieving the regulation of the mechanical properties of the amorphous alloy.
It enables customized control of the mechanical properties of amorphous alloys, improves production efficiency, reduces costs, and enhances plastic deformation capacity while maintaining high strength.
Smart Images
Figure CN122007369A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of amorphous alloy preparation and die casting technology, and more specifically, to a method for controlling the mechanical properties of die-cast amorphous alloys. Background Technology
[0002] Amorphous alloys (also known as metallic glasses) possess extremely high yield strength, high hardness, excellent elastic limit, and corrosion resistance due to their long-range disordered atomic structure, exhibiting great application potential in consumer electronics hinges, precision mechanical transmission components, and medical devices. However, amorphous alloys typically exhibit macroscopic brittleness at room temperature and lack plastic deformation capability, which greatly limits their reliability as critical structural components. Therefore, how to improve their plasticity while maintaining high strength, or how to flexibly adjust their strength-toughness balance according to different application scenarios, has always been a research focus in this field.
[0003] To control the mechanical properties of amorphous alloys, current industry and academia mainly adopt conventional technical approaches such as changing alloy composition, cryogenic cycling, annealing heat treatment, or mechanical pre-deformation. However, these methods all have significant limitations. Specifically, composition control follows a static model of "one composition corresponds to one property." If product performance requirements change, it is necessary to remelt a master alloy with different proportions. This not only significantly increases raw material inventory costs but also leads to frequent cleaning of crucibles and barrels on the production line, severely reducing production efficiency. While cryogenic cycling can induce internal stress and increase free volume through thermal cycling, it is an offline post-processing step that is extremely time-consuming and consumes a lot of liquid nitrogen. Furthermore, the processing effect is often uneven for large-sized or complex irregularly shaped die-cast parts. Annealing usually causes structural relaxation in amorphous alloys, resulting in the annihilation of free volume. Although this can increase hardness, it often leads to further embrittlement of the material. Mechanical pre-deformation, on the other hand, makes it difficult to apply uniform loads to complex, precision, thin-walled parts formed by die casting, easily leading to workpiece damage.
[0004] Vacuum die casting, as the mainstream process for achieving near-net-shape forming of amorphous alloy precision structural parts, boasts advantages in high-speed filling and high-pressure solidification. However, current die casting process optimization primarily focuses on "forming quality," i.e., eliminating macroscopic defects such as porosity and cold shuts by optimizing thermodynamic parameters such as mold temperature, melting temperature, or vacuum level, while largely neglecting the potential of the kinetic parameter "injection rate" to regulate the intrinsic microstructure of the material. In fact, amorphous alloys are thermodynamically metastable materials, and their properties are highly sensitive to shear history. During die casting, the melt flows through the gate and cavity at high speed in an extremely short time, undergoing shear history of up to 10... 3 ~10 5 s -1The intense shear deformation. This shear rejuvenation effect in the rheological process can theoretically change the free volume content and atomic cluster structure inside the material, and is a natural and intense rheological modification method.
[0005] Therefore, there is an urgent need for a new method that does not require changing the alloy composition or adding additional post-processing equipment. Summary of the Invention
[0006] In view of the above problems, the purpose of this invention is to provide a method for controlling the mechanical properties of die-cast amorphous alloys, so as to solve the problems of the single and high cost of existing amorphous alloy property control methods. This invention utilizes the characteristics of high-speed filling and high-pressure solidification in high-vacuum die casting. By applying high shear force during the die-casting filling stage, and subjecting the amorphous melt to severe disturbance under deep supercooling conditions, the shear strain rate is changed by controlling the injection rate, thereby controlling the structural relaxation behavior inside the amorphous alloy. By retaining different degrees of free volume, effective control of the macroscopic mechanical properties (such as hardness, yield strength, etc.) of the amorphous alloy is achieved.
[0007] The above objective is achieved through the following technical solutions: In a first aspect, the present invention provides a vacuum die-casting apparatus, comprising a sealed melting chamber, a melting crucible disposed within the melting chamber and a tilting drive mechanism, a die-casting mold, a material cylinder, an injection rod, a vacuum pump assembly, and a mold temperature controller, wherein... One end of the barrel is connected to the cavity of the die-casting mold, and the other end passes through the melting chamber and is connected to the injection rod; The smelting crucible is mounted on the tilting drive mechanism, which is used to drive the smelting crucible to tilt so as to pour the molten material formed by smelting into the material cylinder; The injection rod is used to inject the molten material in the barrel into the cavity of the die-casting mold; The die-casting mold is used to die-cast the molten material injected into the cavity; The vacuum pump unit is connected to the melting chamber and the die-casting mold, and is used to draw a vacuum. The mold temperature controller is connected to the die-casting mold and is used to preheat the die-casting mold.
[0008] Alternatively, the melting crucible may be a high-temperature resistant ceramic crucible; wherein the high-temperature resistant ceramic crucible is a fused silica-alumina composite ceramic crucible, a zirconia ceramic crucible, or a yttrium oxide ceramic crucible.
[0009] Secondly, the present invention provides a method for controlling the mechanical properties of die-cast amorphous alloys, wherein the above-mentioned vacuum die-casting equipment is used to prepare amorphous alloy structural parts, and the control includes: S1: placing the selected amorphous alloy raw materials into the melting crucible of the vacuum die-casting equipment; S2: Construct a melting vacuum environment in the vacuum die casting equipment; wherein, the die casting mold of the vacuum die casting equipment is preheated so that the preheating temperature of the die casting mold is lower than the glass transition temperature of the amorphous alloy, and the vacuum die casting equipment is vacuum treated so that the vacuum die casting equipment reaches a preset vacuum degree. S3: When the vacuum die-casting equipment heats the melting crucible under the preset vacuum environment, the amorphous alloy raw material in the melting crucible is melted into a molten amorphous alloy melt. S4: Pour the amorphous alloy melt from the melting crucible into the material cylinder; S5: Under the action of the injection rod, the amorphous alloy melt in the barrel is injected into the cavity of the die-casting mold at a preset injection rate; wherein, the shear strain rate of the amorphous alloy melt during filling is controlled by adjusting the injection rate. S6: After the amorphous alloy melt is injected into the cavity, the amorphous alloy melt is held under pressure and solidified. After the holding pressure and solidification are completed, the mold is opened to obtain the amorphous alloy structural part. S7: The prepared amorphous alloy structural parts are processed into standard test dimensions for mechanical property testing. Based on the tested mechanical properties and the injection rate corresponding to the mechanical properties, process parameters that meet the target performance requirements are selected.
[0010] Alternatively, in S5, the step of controlling the shear strain rate of the amorphous alloy melt during filling by adjusting the injection rate includes: determining the magnitude of the injection rate based on the correspondence between the injection rate and the mechanical properties; wherein, The shear strain rate increases with increasing injection rate and decreases with decreasing injection rate.
[0011] Alternatively, in S4, the preset injection rate is 0.5~2.5 m / s; The shear strain rate during the filling of the amorphous alloy melt is 10. 2 ~10 4 s -1 .
[0012] Alternatively, when the amorphous alloy structural component has high hardness, the injection rate can be set to 0.5~1.5 m / s; When the amorphous alloy structural component has high plasticity or toughness, the injection rate is set to 1.5~2.5 m / s.
[0013] Alternatively, in S2, the preheating temperature is 150–250 °C. The preset vacuum level is 10. -3 ~10 2 Pa.
[0014] Alternatively, in S3, the melting temperature of the amorphous alloy raw material is 100-250 °C higher than the liquidus temperature of the amorphous alloy.
[0015] Alternatively, in S4, the pouring rate of the melting crucible is 15–30 ° / s.
[0016] Alternatively, in S5, the holding pressure for solidifying the amorphous alloy melt is 10–300 MPa, and the holding time is 2–10 s. The effective thickness of the amorphous alloy structural component is 0.3–2 mm.
[0017] As can be seen from the above technical solution, the method for controlling the mechanical properties of die-cast amorphous alloys provided by the present invention has the following advantages compared with the prior art: 1) The process controllability of the present invention is strong: The present invention does not require changing the chemical composition of the material, but only changes the injection rate in the die casting process to achieve continuous control of the mechanical properties of amorphous alloys.
[0018] 2) The present invention has high production efficiency: Amorphous alloy structural parts are prepared by vacuum die casting equipment. Based on this die casting technology, the near-net-shape forming and performance control of amorphous alloys can be integrated, thereby avoiding the cumbersome subsequent heat treatment process.
[0019] 3) This invention enables customized control of the mechanical properties of amorphous alloys: Based on the correlation between injection rate and mechanical properties, increasing the injection rate enhances shear disturbance, suppresses structural relaxation of the amorphous alloy, and increases the free volume content, thereby reducing Vickers hardness and improving plastic deformation capacity; or, decreasing the injection rate weakens shear disturbance, thereby increasing Vickers hardness. Utilizing the high shear rheological effect brought about by high injection rate effectively increases the free volume content within the amorphous alloy, thus enabling targeted adjustment of the hardness and plastic deformation capacity of the amorphous alloy material.
[0020] To achieve the foregoing and related objectives, one or more aspects of the invention include the features that will be described in detail below. The following description and accompanying drawings illustrate certain exemplary aspects of the invention. However, these aspects indicate only a few of the various ways in which the principles of the invention can be used. Furthermore, the invention is intended to encompass all such aspects and their equivalents. Attached Figure Description
[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0022] Figure 1 This is a schematic diagram of a vacuum die-casting equipment according to an embodiment of the present invention; Figure 2 The XRD diffraction pattern of the amorphous alloy prepared in Example 1 is shown.
[0023] Figure 3 The image shows the DSC curve of the amorphous alloy prepared in Example 1.
[0024] Figure 4 The image shows the Vickers hardness of the amorphous alloy prepared in Example 1.
[0025] The attached figures are labeled as follows: 1. Melting chamber, 2. Melting crucible, 3. Injection rod, 4. Die casting mold, 5. Material cylinder. Detailed Implementation
[0026] In the following description, numerous specific details are set forth for illustrative purposes and to provide a thorough understanding of one or more embodiments. However, it will be apparent that these embodiments may also be implemented without these specific details. In other instances, well-known structures and devices are shown in block diagram form for ease of description of one or more embodiments.
[0027] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0028] This invention can be modified and has various embodiments, with specific embodiments illustrated in the accompanying drawings. However, this invention is not limited to this particular implementation and all modifications, equivalents, and substitutions falling within the spirit and technical scope of this invention are to be understood as included.
[0029] Ordinal terms such as "first," "second," etc., may be used to describe various constituent elements, but the constituent elements are not limited to these terms. The terms are used only to distinguish one constituent element from another. For example, without departing from the scope of the claims of this invention, a second constituent element may be named a first constituent element, and similarly, a first constituent element may be named a second constituent element. Terms and / or include combinations of multiple associated items or one of multiple associated items.
[0030] It should be understood that when referring to a constituent element being "connected" or "in contact" with other constituent elements, this includes not only cases where it is directly connected or in contact with other constituent elements, but also cases where other constituent elements exist between them. Conversely, when referring to a constituent element being "directly connected" or "directly in contact" with other constituent elements, it should be understood that no other constituent elements exist between them.
[0031] To address the aforementioned problems of limited and costly existing methods for controlling the properties of amorphous alloys, this invention proposes a method for controlling the mechanical properties of die-cast amorphous alloys. This invention combines vacuum die casting with amorphous alloys to control the mechanical properties of the formed amorphous alloy structural parts. By changing the injection rate to alter the shear strain rate experienced by the melt during filling, and by specifically adjusting the material's hardness and plastic deformation capacity, this invention offers a simple and rapid manufacturing process, reducing time costs. Furthermore, the control method provided by this invention can be applied to the mechanical property control of amorphous alloy die casting.
[0032] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.
[0033] To illustrate the structure of the vacuum die-casting equipment provided by the present invention, Figure 1 The structure of a vacuum die-casting apparatus according to an embodiment of the present invention is shown.
[0034] like Figure 1 As shown, the present invention provides a vacuum die-casting device, including a sealed melting chamber 1, a melting crucible 2 disposed in the melting chamber 1, a tilting drive mechanism, a die-casting mold 4, a material cylinder 5, and an injection rod 3. One end of the material cylinder 5 is connected to the cavity of the die-casting mold 4, and the other end passes through the melting chamber 1 and is connected to the injection rod 3. The melting crucible 2 is mounted on the tilting drive mechanism, which drives the melting crucible to tilt and pour the molten material into the material cylinder 5. Under the action of the injection rod 3, the material cylinder 5 injects the molten material into the cavity of the die-casting mold 4. The die-casting mold 4 is used to die-cast the molten material injected into the cavity.
[0035] In other words, the melting crucible 2 is placed inside the melting chamber 1 and suspended above the barrel 5 and the injection rod 3 to facilitate the transfer of the melt; the front end of the barrel 5 is in close communication with the cavity of the die-casting mold 4, and the injection rod 3 reciprocates inside the barrel 5 to drive the melt to be pressed into the die-casting mold 4.
[0036] Furthermore, the integrated vacuum melting and die casting equipment of the present invention also includes a vacuum pump unit and a mold temperature controller; the vacuum pump unit is connected to the melting chamber and the die casting mold and is used to create a vacuum; the mold temperature controller is connected to the die casting mold and is used to preheat the die casting mold. The components of the entire equipment work together to achieve a complete vacuum process from melting and injection to solidification.
[0037] The melting crucible 2 is a high-temperature resistant ceramic crucible; specifically, the high-temperature resistant ceramic crucible is a fused silica-alumina composite ceramic crucible, a zirconia ceramic crucible, or a yttrium oxide ceramic crucible. The vacuum die-casting equipment of this invention aims to achieve vacuum environmental protection throughout the melting, filling, and solidification processes, providing a basis for methods to control the mechanical properties of die-cast amorphous alloys.
[0038] To illustrate the method for controlling the mechanical properties of die-cast amorphous alloys provided by the present invention, the method for controlling the mechanical properties of die-cast amorphous alloys provided by the present invention uses the above-mentioned vacuum die-casting equipment to prepare amorphous alloy structural parts. The method includes: S1: placing the selected amorphous alloy raw materials into the melting crucible of the vacuum die-casting equipment. S2: Construct a melting vacuum environment in the vacuum die casting equipment; wherein, the die casting mold of the vacuum die casting equipment is preheated so that the preheating temperature of the die casting mold is lower than the glass transition temperature of the amorphous alloy, and the vacuum die casting equipment is vacuum treated so that the vacuum die casting equipment reaches a preset vacuum degree. S3: When the vacuum die-casting equipment heats the melting crucible under the preset vacuum environment, the amorphous alloy raw material in the melting crucible is melted into a molten amorphous alloy melt. S4: Pour the amorphous alloy melt from the melting crucible into the material cylinder; S5: Under the action of the injection rod, the amorphous alloy melt in the barrel is injected into the cavity of the die-casting mold at a preset injection rate; wherein, the shear strain rate of the amorphous alloy melt during filling is controlled by adjusting the injection rate. S6: After the amorphous alloy melt is injected into the cavity, the amorphous alloy melt is held under pressure and solidified. After the holding pressure and solidification are completed, the mold is opened to obtain the amorphous alloy structural part. S7: The prepared amorphous alloy structural parts are processed into standard test dimensions for mechanical property testing. Based on the tested mechanical properties and the injection rate corresponding to the mechanical properties, process parameters that meet the target performance requirements are selected.
[0039] This invention utilizes the characteristics of high-speed filling and high-pressure solidification in high-vacuum die casting. By applying high shear during the die casting filling stage, and subjecting the amorphous melt to severe disturbance under deep supercooling conditions, the shear strain rate is altered by controlling the injection rate. This, in turn, controls the structural relaxation behavior within the amorphous alloy. By retaining varying degrees of free volume, the macroscopic mechanical properties of the amorphous alloy (such as hardness and yield strength) can be effectively controlled.
[0040] In S5, the step of controlling the shear strain rate of the amorphous alloy melt during filling by adjusting the injection rate includes: determining the magnitude of the injection rate based on the correspondence between the injection rate and the mechanical properties; wherein the shear strain rate increases with increasing injection rate and decreases with decreasing injection rate.
[0041] In other words, in this invention, the relationship between injection rate and mechanical properties is based on: increasing the injection rate to enhance shear disturbance, suppressing structural relaxation of amorphous alloys and increasing free volume content, thereby reducing Vickers hardness and improving plastic deformation capacity; or decreasing the injection rate to weaken shear disturbance, thereby increasing Vickers hardness.
[0042] In S5, the preset injection rate is 0.5~2.5 m / s; the shear strain rate during the filling of the amorphous alloy melt is 10. 2 ~10 4 s -1 When the amorphous alloy structural component has high hardness, the injection rate is set to 0.5~1.5 m / s (inclusive); when the amorphous alloy structural component has high plasticity or toughness, the injection rate is set to 1.5~2.5 m / s (inclusive). That is, the injection rate corresponding to the shear mode is 0.5~1.5 m / s (inclusive), and the injection rate corresponding to the high shear mode is 1.5~2.5 m / s (inclusive).
[0043] In S2, to reduce the temperature difference between the melt and the mold, delay early solidification during thin-wall filling, improve surface finish, and reduce filling resistance, the preheating temperature is set to 150–250 °C. To prevent secondary oxidation inclusions in the amorphous alloy at high-temperature molten state and suppress crystallization, the preset vacuum degree is set to 10. -3 ~10 2Pa. In S3, to ensure good melt flowability, the melting temperature of the amorphous alloy raw material is 100-250 °C higher than the liquidus of the amorphous alloy. The melting temperature setting must consider both good melt flowability and mold life. Too low a temperature results in poor flowability, while too high a temperature has a greater impact on mold life. For Vit106 amorphous alloy, a temperature of 950-1100 °C is preferred.
[0044] In S4, during the pouring of the amorphous alloy melt, in order to maintain the continuity and stability of melt delivery, reduce heat loss, and prevent liquid splashing and entrainment of residual gas in the vacuum chamber due to excessive pouring speed, the pouring rate of the melting crucible is set to 15-30 ° / s.
[0045] In step S5, to eliminate internal shrinkage cavities and improve dimensional accuracy, the holding pressure for solidifying the amorphous alloy melt is set to 10–300 MPa, and the holding time is 2–10 s. The effective thickness or maximum diameter of the amorphous alloy structural component is smaller than the critical casting size of the alloy composition, preferably 0.3–2 mm.
[0046] To illustrate the effects of this invention in detail, specific embodiments are provided below. Unless otherwise specified, the raw materials used in the embodiments of this invention are all purchased commercially, i.e., industrial-grade raw materials.
[0047] Example 1
[0048] This embodiment provides a method for controlling the mechanical properties of die-cast amorphous alloys, such as... Figures 1 to 4 As shown, the method includes the following steps (steps one through seven).
[0049] Step 1: Selection of Amorphous Alloy Raw Materials
[0050] According to Zr 56 Cu 15.7 Ni 13.2 Al 10.4 Nb 4.7 The atomic percentages of the raw materials were calculated and industrially pure elemental raw materials were weighed. A total of 5 kg of master alloy was prepared, containing: 3361.6 g of zirconium (Zr), 656.5 g of copper (Cu), 509.8 g of nickel (Ni), 184.7 g of aluminum (Al), and 287.4 g of niobium (Nb). The prepared raw materials were placed in high-purity (99.99%) argon gas and induction melted into a complete ingot. The ingot was then crushed into granular master alloy particles with a particle size of less than 2 cm using a crusher.
[0051] Step 2: Smelting of amorphous alloy raw materials
[0052] The alloyed master alloy granules are added to the melting crucible 2 inside the melting chamber 1 of the vacuum die-casting equipment. The chamber door is then locked and the mold is closed. The vacuum level inside the equipment is evacuated to 10. -1 Pa, start the melting crucible 2 to melt the master alloy granules into a melt, and set the melting temperature to 950 ℃.
[0053] Step 3: Transfer of amorphous alloy melt
[0054] After the amorphous alloy raw material is completely melted into an amorphous alloy melt, the amorphous alloy melt is quickly poured into the barrel 5 by controlling the rotating melting crucible 2 and setting the tilting rate to 15 ° / s.
[0055] Step 4: Injection of amorphous alloy melt
[0056] By setting the injection rate to 0.5 m / s, the injection rod 3 rapidly presses the amorphous melt into the cavity of the die-casting mold 4. The initial temperature of the die-casting mold 4 is set to 150 ℃ (to ensure deep supercooling conditions).
[0057] Step 5: Solidification of amorphous alloy structural components
[0058] After the filling stage is completed, the holding pressure is set to 150 MPa. The amorphous melt is solidified under pressure by the action of the injection rod 3, ensuring the smooth molding of the amorphous alloy.
[0059] Step Six: Mold Opening and Part Removal
[0060] After the casting temperature cools down to below 350 ℃, the mold is opened and the amorphous alloy structural part is removed.
[0061] Step 7: Adjust the injection rate
[0062] Repeat steps one through six above, adjusting the injection rate to 1.0 m / s, 1.5 m / s, 2.0 m / s, and 2.5 m / s respectively. Prepare all die-cast amorphous alloy structural parts to the specified dimensions using a slow-speed diamond slicing machine for the next experimental test.
[0063] X-ray diffraction (XRD) test: The structural characteristics of the amorphous alloy obtained in this embodiment were determined by X-ray diffraction (XRD) (the materials prepared in Examples 2 and 3 were tested using this method). Figure 2 The XRD diffraction patterns of the amorphous alloys formed at different injection rates in this embodiment are shown. In the XRD patterns of the amorphous alloys obtained under all injection rate conditions in this embodiment, the typical broad peaks characteristic of amorphous alloy materials can be clearly observed. This demonstrates that all amorphous alloy materials prepared under these process conditions possess a good amorphous structure.
[0064] Differential scanning calorimetry (DSC) test: The amorphous alloy obtained in this embodiment was sampled and subjected to differential scanning calorimetry (the materials prepared in Examples 2 and 3 were also tested using this method). Figure 3 The DSC curves of the amorphous alloys formed at different injection rates in this embodiment are shown. In the DSC curves of the amorphous alloys obtained under all injection rate conditions in this embodiment, it can be clearly observed that the thermodynamic properties of the amorphous alloy material change with the injection rate; its glass transition point decreases significantly with increasing injection rate.
[0065] Mechanical performance evaluation: The amorphous material obtained in this embodiment was successively polished with sandpaper of 180-2000 grit, and its Vickers hardness was measured (the materials prepared in Examples 2 and 3 were also tested using this method). The surface of the amorphous alloy sample formed at each injection rate was subjected to 20 Vickers hardness tests. The highest and lowest values were removed, and the average value was taken as the Vickers hardness. The results show that the Vickers hardness of the amorphous alloy gradually decreases as the injection rate increases.
[0066] By controlling the injection rate in the vacuum die casting process described above, the shear strain rate during the solidification process of the amorphous alloy melt is changed. Under this deep supercooling condition, the disturbance effect achieves the control of the mechanical properties of the amorphous alloy.
[0067] Example 2
[0068] Step 1: Selection of Amorphous Alloy Raw Materials
[0069] According to Zr 65 Cu 17.5 Al 7.5 Ni 10 The atomic percentages were calculated and industrially pure elemental raw materials were weighed. A total of 5 kg of master alloy was prepared, containing: 3786.0 g of zirconium (Zr), 710.0 g of copper (Cu), 374.8 g of nickel (Ni), and 129.2 g of aluminum (Al). The prepared elemental raw materials were placed in high-purity (99.99%) argon gas and induction melted into a complete ingot. The ingot was then crushed into granular master alloy particles with a particle size of less than 2 cm using a crusher.
[0070] Step Two: Melting of Amorphous Alloys
[0071] The alloyed master alloy granules are added to the melting crucible 2 inside the melting chamber 1. The chamber door is locked and the mold is closed. The vacuum level inside the equipment is evacuated to 10 Pa, and the melting crucible 2 is started to melt the master alloy granules into a melt. The melting temperature is set to 1000 °C.
[0072] Step 3: Transfer of amorphous alloy melt
[0073] After melting is completed, the amorphous alloy melt is quickly poured into the barrel by controlling the rotation of the melting crucible and setting the tilting rate to 20 ° / s.
[0074] Step 4: Injection of amorphous alloy melt
[0075] By setting the injection rate to 0.5 m / s, the injection rod 3 rapidly presses the amorphous melt into the cavity of the die-casting mold 4. The initial temperature of the die-casting mold 4 is set to 180 ℃ (to ensure deep supercooling conditions).
[0076] Step 5: Solidification of amorphous alloy structural components
[0077] After the filling stage is completed, the holding pressure is set to 100 MPa. The amorphous melt is solidified under pressure by the action of the injection rod 3, ensuring the smooth molding of the amorphous alloy.
[0078] Step Six: Mold Opening and Part Removal
[0079] After the casting temperature cools down to below 350 ℃, the mold is opened and the amorphous alloy structural part is removed.
[0080] Step 7: Adjust the injection rate
[0081] Repeat steps one through six above, adjusting the injection rate to 1.0 m / s, 1.5 m / s, 2.0 m / s, and 2.5 m / s respectively. Prepare all die-cast amorphous alloy parts to the specified dimensions using a slow-speed diamond slicing machine for the next experimental test.
[0082] Tests were conducted on the Zr65-based amorphous alloy samples, and the results showed that as the injection rate increased from 0.5 m / s to 2.5 m / s, the Vickers hardness of the material decreased, while the plastic strain capacity significantly increased. This confirms that the shear control method described in this invention is universally applicable to zirconium-based amorphous alloys with different compositions.
[0083] Example 3
[0084] Step 1: Selection of Amorphous Alloy Raw Materials
[0085] According to Zr 52 Ti 5.5 Cu 17.9 Ni 14.6 Al10 The atomic percentages were calculated and industrially pure elemental raw materials were weighed. A total of 5 kg of master alloy was prepared, containing: 3262.0 g of zirconium (Zr), 181.1 g of titanium (Ti), 782.2 g of copper (Cu), 589.2 g of nickel (Ni), and 185.5 g of aluminum (Al). The prepared elemental raw materials were placed in high-purity (99.99%) argon gas and induction melted into a complete ingot. The ingot was then crushed into granular master alloy particles with a particle size of less than 2 cm using a crusher.
[0086] Step Two: Melting of Amorphous Alloys
[0087] The alloyed master alloy granules are added to the melting crucible 2 inside the melting chamber 1. The chamber door is locked and the mold is closed. The vacuum level inside the equipment is evacuated to 10. 2 Pa, start the melting crucible 2 to melt the master alloy granules into a melt, and set the melting temperature to 1100 ℃.
[0088] Step 3: Transfer of amorphous alloy melt
[0089] After melting is completed, the amorphous alloy melt is quickly poured into the barrel 5 by controlling the rotating melting crucible 2 and setting the tilting rate to 30 ° / s.
[0090] Step 4: Injection of amorphous alloy melt
[0091] By setting the injection rate to 0.5 m / s, the injection rod 3 rapidly presses the amorphous melt into the cavity of the die-casting mold 4. The initial temperature of the die-casting mold 4 is set to 200 ℃ (to ensure deep supercooling conditions).
[0092] Step 5: Solidification of amorphous alloy structural components
[0093] After the filling stage is completed, the holding pressure is set to 200 MPa. The amorphous melt is solidified under pressure by the action of the injection rod 3, ensuring the smooth molding of the amorphous alloy.
[0094] Step Six: Mold Opening and Part Removal
[0095] After the casting temperature cools down to below 350 ℃, the mold is opened and the amorphous alloy structural part is removed.
[0096] Step 7: Adjust the injection rate
[0097] Repeat steps one through six above, adjusting the injection rate to 1.0 m / s, 1.5 m / s, 2.0 m / s, and 2.5 m / s respectively. Prepare all die-cast amorphous alloy structural parts to the specified dimensions using a slow-speed diamond slicing machine for the next experimental test.
[0098] Similarly, significant softening of mechanical properties and enhancement of plasticity were observed in titanium-containing Zr52-based amorphous alloys under high-speed injection (high shear) conditions, further verifying the effectiveness of controlling the rheological behavior and mechanical properties of amorphous alloys by injection rate.
[0099] The above are merely preferred embodiments of the present invention and do not limit the scope of protection of the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any changes, modifications, substitutions, integrations, and parameter alterations to these embodiments within the spirit and principles of the present invention, achieved through conventional substitutions or by achieving the same function without departing from the principles and spirit of the present invention, fall within the scope of protection of the present invention.
Claims
1. A vacuum die-casting equipment, characterized in that, It includes a sealed melting chamber, a melting crucible and a tilting drive mechanism disposed within the melting chamber, a die-casting mold, a barrel, an injection rod, a vacuum pump assembly, and a mold temperature controller, wherein, One end of the barrel is connected to the cavity of the die-casting mold, and the other end passes through the melting chamber and is connected to the injection rod; The smelting crucible is mounted on the tilting drive mechanism, which is used to drive the smelting crucible to tilt so as to pour the molten material formed by smelting into the material cylinder; The injection rod is used to inject the molten material in the barrel into the cavity of the die-casting mold; The die-casting mold is used to die-cast the molten material injected into the cavity; The vacuum pump unit is connected to the melting chamber and the die-casting mold, and is used to draw a vacuum. The mold temperature controller is connected to the die-casting mold and is used to preheat the die-casting mold.
2. The vacuum die-casting equipment according to claim 1, characterized in that, The smelting crucible is a high-temperature resistant ceramic crucible; wherein, the high-temperature resistant ceramic crucible is a fused silica-alumina composite ceramic crucible, a zirconia ceramic crucible, or a yttrium oxide ceramic crucible.
3. A method for controlling the mechanical properties of die-cast amorphous alloys, characterized in that, Amorphous alloy structural parts are prepared using the vacuum die-casting equipment as described in claim 1 or 2, wherein the control includes: S1: Place the selected amorphous alloy raw material into the melting crucible of the vacuum die-casting equipment; S2: Construct a melting vacuum environment in the vacuum die casting equipment; wherein, the die casting mold of the vacuum die casting equipment is preheated so that the preheating temperature of the die casting mold is lower than the glass transition temperature of the amorphous alloy, and the vacuum die casting equipment is vacuum treated so that the vacuum die casting equipment reaches a preset vacuum degree. S3: When the vacuum die-casting equipment heats the melting crucible under the preset vacuum environment, the amorphous alloy raw material in the melting crucible is melted into a molten amorphous alloy melt. S4: Pour the amorphous alloy melt from the melting crucible into the material cylinder; S5: Under the action of the injection rod, the amorphous alloy melt in the barrel is injected into the cavity of the die-casting mold at a preset injection rate; wherein, the shear strain rate of the amorphous alloy melt during filling is controlled by adjusting the injection rate. S6: After the amorphous alloy melt is injected into the cavity, the amorphous alloy melt is held under pressure and solidified. After the holding pressure and solidification are completed, the mold is opened to obtain the amorphous alloy structural part. S7: The prepared amorphous alloy structural parts are processed into standard test dimensions for mechanical property testing. Based on the tested mechanical properties and the injection rate corresponding to the mechanical properties, process parameters that meet the target performance requirements are selected.
4. The method for controlling the mechanical properties of die-cast amorphous alloys according to claim 3, characterized in that, In S5, controlling the shear strain rate of the amorphous alloy melt during filling by adjusting the injection rate includes: determining the magnitude of the injection rate based on the correspondence between the injection rate and the mechanical properties; wherein, The shear strain rate increases with increasing injection rate and decreases with decreasing injection rate.
5. The method for controlling the mechanical properties of die-cast amorphous alloys according to claim 4, characterized in that, In S4, the preset injection rate is 0.5~2.5 m / s; The shear strain rate during the filling of the amorphous alloy melt is 10. 2 ~10 4 s -1 .
6. The method for controlling the mechanical properties of die-cast amorphous alloys according to claim 5, characterized in that, When the amorphous alloy structural component has high hardness, the injection rate is set to 0.5~1.5 m / s; When the amorphous alloy structural component has high plasticity or toughness, the injection rate is set to 1.5~2.5 m / s.
7. The method for controlling the mechanical properties of die-cast amorphous alloys according to claim 3, characterized in that, In S2, the preheating temperature is 150–250 °C; The preset vacuum level is 10. -3 ~10 2 Pa.
8. The method for controlling the mechanical properties of die-cast amorphous alloys according to claim 3, characterized in that, In S3, the melting temperature of the amorphous alloy raw material is 100~250 °C higher than the liquidus temperature of the amorphous alloy.
9. The method for controlling the mechanical properties of die-cast amorphous alloys according to claim 3, characterized in that, In S4, the tilting rate of the melting crucible is 15–30 ° / s.
10. The method for controlling the mechanical properties of die-cast amorphous alloys according to claim 3, characterized in that, In S5, the holding pressure for solidifying the amorphous alloy melt is 10–300 MPa, and the holding time is 2–10 s. The effective thickness of the amorphous alloy structural component is 0.3–2 mm.