Semi-rigid constraint friction additive manufacturing device and method with high material utilization rate

Abstract

The invention relates to a semi-rigid constraint friction additive manufacturing device and method, in particular to a semi-rigid constraint friction additive manufacturing device and method with the high material utilization rate. The invention aims to solve the problems of low material utilization rate and high improvement cost of two technical branches of friction deposition additive manufacturing based on bar raw materials. The device comprises a semi-rigid constraint body, a temperature control counterweight body, two wire feeding wheels, a bar raw material, a component to be subjected to material addition and a deposition layer. The deposition layer is arranged on the upper surface of a to-be-added component, the temperature control balance weight body is arranged on the upper surface of the deposition layer, the semi-rigid constraint body is arranged in the temperature control balance weight body, the lower surface of the semi-rigid constraint body is attached to the upper surface of the deposition layer, and the lower end of a bar raw material penetrates through a through hole in the upper surface of the temperature control balance weight body and then is inserted into the semi-rigid constraint body. The two wire feeding wheels are symmetrically arranged on the two sides of a plate raw material. The invention belongs to the technical field of solid phase additive manufacturing.

Description

Technical Field

[0001] The invention relates to a semi-rigid constrained friction additive manufacturing device and method, belonging to the technical field of solid-phase additive manufacturing. Background Art

[0002] Solid-phase additive manufacturing based on the principle of large plastic deformation is attracting widespread attention due to its advantages such as low thermal damage to non-melting materials, no intrinsic defects due to solidification, fine graining of strong deformation structure, low energy consumption and high forming efficiency. Among this type of technology, there is a main category of friction deposition additive manufacturing methods based on the feeding of bar raw materials. Its basic principle is to generate heat by rotating the bar raw materials at high speed and rubbing against the surface of the component to be added at a certain speed / upsetting force, so that the end face of the bar is locally thermally plasticized and continuously deposited on the surface of the additive component to form a solid phase deposition layer. This process avoids the defects of element burning, pore cracks, and weak connection interface of oxide film in the melting additive manufacturing process in principle. At the same time, the extrusion deposition layer of the additive tool plays a "forging" role in the forming process, forming an ultra-fine grained structure with high strength and toughness, and the comprehensive strength and plasticity exceed the level of forgings.

[0003] This type of friction deposition additive manufacturing based on rod raw materials has formed two technical branches in its research and development process: 1. The first is the unconstrained rod deposition mode, namely the Friction Surfacing technology. This type of method has extremely low equipment requirements and can be easily carried out on any CNC machine tool that can perform milling or stir friction welding. However, since there is no rigid constraint on its end face, the material will inevitably form curling edges, also known as flash, during the deposition process, resulting in extremely low material utilization, usually less than 50%, and the deposited layer is usually rough and the forming quality is average; 2. In response to the technical bottleneck of the previous technical branch, relevant scholars have proposed a fully rigidly constrained rod deposition mode, namely additive stir friction deposition. Deposition technology changes the round bar of friction surfacing into a square bar, and the sharp edge of the square bar rotates synchronously with a rigid constraint body that matches the profile. The square bar is fed in through a thrust electric cylinder or hydraulic cylinder at the end. This change fundamentally avoids the formation of curling, greatly improves the material utilization rate, and improves the forming quality of the deposited layer appearance. However, due to the significant change in structure, especially the existence of the synchronously rotating rigid constraint body and the end thrust structure, most existing equipment cannot be operated through simple modification, limiting the potential for the promotion and application of this type of technology. In view of this, if a simple and easy-to-implement constraint method can be proposed, which on the one hand inhibits the formation of curling, on the other hand has significant characteristics of easy modification and low cost, while taking into account a class of effects such as low heat input or temperature control ability, it will greatly expand the breadth and depth of application of friction deposition additive manufacturing based on bar raw materials. Summary of the invention

[0004] In order to solve the problems of low material utilization and high transformation cost in the two existing technical branches of friction deposition additive manufacturing based on rod raw materials, the present invention further proposes a semi-rigid constrained friction additive manufacturing device and method with high material utilization.

[0005] The technical solution adopted by the present invention to solve the above problems is: the semi-rigid constrained friction additive manufacturing device of the present invention comprises a semi-rigid constrained body, a temperature-controlled counterweight body, two wire feeding wheels, a rod raw material, a component to be added and a deposition layer;

[0006] The deposition layer is arranged on the upper surface of the component to be added, the temperature-controlled counterweight is arranged on the upper surface of the deposition layer, the semi-rigid constraint is arranged in the temperature-controlled counterweight, and the lower surface of the semi-rigid constraint is in contact with the upper surface of the deposition layer. The lower end of the rod raw material passes through the through hole on the upper surface of the temperature-controlled counterweight and is inserted into the semi-rigid constraint. Two wire feeding wheels are symmetrically arranged on both sides of the plate raw material.

[0007] Further, it also includes a thrust roller bearing;

[0008] The inner ring of the thrust roller bearing is coaxially fixedly sleeved on the bar stock, and the thrust roller bearing is located between the upper surface of the semi-rigid constraint body and the inner top surface of the temperature-controlled counterweight body.

[0009] Furthermore, a central hole penetrating the upper and lower surfaces of the semi-rigid constraint body is provided in the middle of the semi-rigid constraint body, and an upper edge chamfer is provided at the edge of the opening of the central hole.

[0010] Furthermore, a central stepped hole penetrating the upper and lower surfaces of the temperature control counterweight body is provided in the middle of the temperature control counterweight body, and the central stepped hole is composed of an upper central stepped hole portion and a lower central stepped hole portion;

[0011] An annular liquid cooling inner flow channel is arranged in the temperature control counterweight body, and a cooling medium inflow hole and a cooling medium outflow hole which are connected with the liquid cooling inner flow channel are symmetrically arranged on the outer wall of the temperature control counterweight body.

[0012] The specific steps of the semi-rigid constrained friction additive manufacturing method of the present invention include:

[0013] Step 1: Coaxially assemble the semi-rigid constraint body, the temperature-controlled counterweight body, and the thrust roller bearing, and place them at the starting point of the component to be added;

[0014] Step 2: The rod raw material rotates at high speed and passes through the central hole of the semi-rigid constraint body under the clamping and feeding action of the feeding wheel to generate heat by friction with the component to be added;

[0015] Step 3: The semi-rigid constraint body forms a radial constraint on the end face of the rod raw material, and combined with the weight of the temperature-controlled counterweight body, effectively inhibits the formation of curling, improves material utilization, and forms a dense and well-formed deposition layer.

[0016] The beneficial effects of the present invention are:

[0017] 1. The present invention proposes a semi-rigid constraint friction additive manufacturing device and method. The semi-rigid constraint body forms a radial constraint on the end surface of the rod raw material, and combined with the weight of the temperature-controlled counterweight body, it can effectively suppress the formation of curling and improve material utilization. At the same time, the composite structure of the semi-rigid constraint body and the temperature-controlled counterweight body is not connected to the CNC machine tool and does not involve any equipment modification, which has the significant characteristics of easy modification and low cost;

[0018] 2. The semi-rigid constraint of the present invention is not driven by any other power during use, has no axial upsetting force, and does not generate frictional heat with the component to be added or the deposited layer. Unlike the additive friction stir deposition technology, it does not bring additional heat input to the rigid constraint and thermal damage to the material.

[0019] 3. The temperature-controlled counterweight designed in the present invention can optionally pass a cooling medium or not to cool the deposited layer to control the temperature, further reducing thermal damage during the additive manufacturing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of a semi-rigid constrained friction additive manufacturing device with high material utilization rate;

[0021] Figure 2 It is a schematic diagram of the structure of a semi-rigid constrained friction additive manufacturing device in a round bar mode;

[0022] Figure 3 is a schematic diagram of the structure of a semi-rigid constrained friction additive manufacturing device in a square bar mode;

[0023] Figure 4 It is a semi-rigid constraint in the round bar mode;

[0024] Figure 5 It is a semi-rigid constraint in the square bar mode;

[0025] Figure 6 is a schematic diagram of a temperature-controlled counterweight;

[0026] Figures 1 to 6In the figure, 1-semi-rigid constraint, 1A-semi-rigid constraint in round bar mode, 1B-semi-rigid constraint in square bar mode, 101-center hole, 102-center hole upper edge chamfer, 2-temperature controlled counterweight, 201-upper part of center step hole, 202-lower part of center step hole, 203-liquid cooling inner flow channel, 20301-cooling medium inflow hole, 20302-cooling medium outflow hole, 3-thrust roller bearing, 4-wire feeding wheel, 5-rod raw material, 5A-round rod, 5B-square rod, 6-component to be added, 7-deposition layer. DETAILED DESCRIPTION

[0027] Specific implementation method 1: Figure 1 As shown, a semi-rigid constrained friction additive manufacturing device with high material utilization rate includes a semi-rigid constrained body 1, a temperature-controlled counterweight body 2, two wire feeding wheels 4, a rod raw material 5, a component to be added 6 and a deposition layer 7;

[0028] The deposition layer 7 is arranged on the upper surface of the component to be added 6, the temperature-controlled counterweight body 2 is arranged on the upper surface of the deposition layer 7, the semi-rigid constraint body 1 is arranged in the temperature-controlled counterweight body 2, and the lower surface of the semi-rigid constraint body 1 is in contact with the upper surface of the deposition layer 7, the lower end of the rod raw material 5 passes through the through hole on the upper surface of the temperature-controlled counterweight body 2 and is inserted into the semi-rigid constraint body 1, and two wire feeding wheels 4 are symmetrically arranged on both sides of the plate raw material 5.

[0029] Wherein, the thrust roller bearing 3 is used to isolate the rotational motion between the rotating or non-rotating semi-rigid constraint body 1 and the non-rotating temperature-controlled counterweight body 2;

[0030] The feeding wheels 4 are two rotating bodies with gear structures, which are used to clamp the bar material 5 symmetrically laterally and feed the bar material at a constant speed or constant pressure, and they rotate synchronously with the bar material 5 at a high speed;

[0031] Among them, the rod raw material 5 is the raw material used for friction deposition additive manufacturing, including but not limited to aluminum and aluminum alloys, magnesium and magnesium alloys, copper and copper alloys, steel, titanium and titanium alloys, metal-based composites, thermoplastic polymers and their composites, etc.

[0032] Specific implementation method 2: Figure 1 As shown, based on the specific implementation mode 1, a thrust roller bearing 3 is also included;

[0033] The inner ring of the thrust roller bearing 3 is coaxially fixedly sleeved on the rod raw material 5 , and the thrust roller bearing 3 is located between the upper surface of the semi-rigid constraint body 1 and the inner top surface of the temperature-controlled counterweight body 2 .

[0034] Specific implementation method three: Figure 4 and Figure 5As shown, based on the first specific implementation mode, a center hole 101 penetrating the upper and lower surfaces of the semi-rigid constraint body 1 is provided in the middle of the semi-rigid constraint body 1 , and an upper edge chamfer 102 is provided at the edge of the hole opening of the center hole 101 .

[0035] The center hole 101 can adopt different center hole structures according to different forms of the rod raw materials, that is, when the round rod raw material 5A is used, the center hole is a circle 1A, and its center hole diameter is 0.2-0.6mm larger than the diameter of the round rod raw material 5A; when the square rod raw material 5B is used, the center hole is a square 1B, and its diagonal length is 0.3-0.9mm larger than the diagonal length of the square rod raw material 5B. A chamfer 102 is provided on the upper edge of the center hole 101 to facilitate the rod raw material 5 to pass through the semi-rigid constraint 1;

[0036] During use, the semi-rigid constraint 1 only moves with the movement of the rod material 5 and is not driven by any other power.

[0037] Specific implementation method four: Figure 6 As shown, on the basis of the specific implementation mode 1, a central stepped hole penetrating the upper and lower surfaces of the temperature control counterweight body 2 is provided in the middle of the temperature control counterweight body 2, and the central stepped hole is composed of a central stepped hole upper part 201 and a central stepped hole lower part 202;

[0038] An annular liquid cooling inner flow channel 203 is provided in the temperature control counterweight body 2 , and a cooling medium inlet hole 20301 and a cooling medium outlet hole 20302 communicating with the liquid cooling inner flow channel 203 are symmetrically provided on the outer side wall of the temperature control counterweight body 2 .

[0039] The diameter of the upper portion 201 of the central stepped hole is greater than the diameter of the round rod raw material 5A or the diagonal length of the square rod raw material 5B by more than 1.0 mm, and the diameter of the lower portion 202 of the central stepped hole is greater than the outer diameter of the semi-rigid constraint body 1 by 0.2 to 0.5 mm, and the height of the lower portion should be consistent with the sum of the heights of the semi-rigid constraint body 1 and the thrust roller bearing 3, so as to ensure that the lower surface thereof fits the deposition layer 7 during the additive manufacturing process;

[0040] The liquid-cooled inner flow channel 203 is provided with a cooling medium inlet hole 203012 and an outlet hole 20302, which are used to continuously cool and temperature control the deposited layer 7, further reducing the thermal damage caused by the heat of additive manufacturing. At the same time, due to the presence of the thrust roller bearing 3, it moves with the rod raw material 5 but does not rotate during the friction deposition process, so that the cooling temperature control can be carried out continuously; at the same time, the structure can be made of high-density, high-thermal conductivity materials such as copper or tungsten. Its large weight can ensure that the semi-rigid constraint 1 will not be accidentally pushed open during the additive manufacturing process, thereby achieving the effect of counterweight stabilization.

[0041] Specific implementation method five: Figures 1 to 6 As shown, a semi-rigid constrained friction additive manufacturing method with high material utilization rate comprises the following specific steps:

[0042] Step 1, coaxially assemble the semi-rigid constraint body 1, the temperature-controlled counterweight body 2, and the thrust roller bearing 3, and place them at the starting point of the component to be added 6;

[0043] Step 2: The rod material 5 rotates at high speed and passes through the central hole 101 of the semi-rigid constraint body 1 under the clamping and feeding action of the feeding wheel 4 to generate heat by friction with the component to be added 6;

[0044] Step 3: The semi-rigid constraint body 1 forms a radial constraint on the end face of the rod raw material 5, and combined with the weight of the temperature-controlled counterweight body 2, effectively suppresses the formation of curling, improves material utilization, and forms a dense and well-formed deposition layer 7.

[0045] Among them, if the semi-rigid constraint body 1 uses a round rod raw material 5A during use, the high-speed rotation of the round rod raw material 5A usually does not drive or only occasionally drives the semi-rigid constraint body 1A to rotate together, and the whole presents a non-rotating or low-speed discontinuous rotation follow-up state. Moreover, since it is not driven by any other power, there is no axial forging force, and there is no frictional heat generation between the component to be added 6 or the deposition layer 7. Unlike the additive stirring friction deposition technology, it will not bring additional heat input to the rigid constraint body 1A and thermal damage to the material; if the square rod raw material 5B is used, the semi-rigid constraint body 1A rotates synchronously with the square rod raw material 5B, but since it is also not driven by any other power, there is no axial forging force, and there is no frictional heat generation between the component to be added 6 or the deposition layer 7, and there will be no additional heat input to the rigid constraint body 1B and thermal damage to the material.

[0046] Among them, in the semi-rigid constrained friction additive manufacturing device and method, the cooling medium can be optionally passed through the temperature-controlled counterweight body 2 to cool and control the temperature of the deposited layer 7 and reduce thermal damage during the additive manufacturing process.

[0047] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent replacement and improvement made to the above embodiments without departing from the content of the technical solution of the present invention, based on the technical essence of the present invention, within the spirit and principles of the present invention, still fall within the protection scope of the technical solution of the present invention.

Claims

1. A semi-rigid constrained friction additive manufacturing device with high material utilization, characterized in that: It comprises a semi-rigid constraint body (1), a temperature-controlled counterweight body (2), two wire feeding wheels (4), a rod material (5), a component to be added (6) and a deposition layer (7); The deposition layer (7) is arranged on the upper surface of the component (6) to be added with material, the temperature-controlled counterweight (2) is arranged on the upper surface of the deposition layer (7), the semi-rigid constraint (1) is arranged in the temperature-controlled counterweight (2), and the lower surface of the semi-rigid constraint (1) is in contact with the upper surface of the deposition layer (7), the lower end of the rod material (5) passes through the through hole on the upper surface of the temperature-controlled counterweight (2) and is inserted into the semi-rigid constraint (1), and two wire feeding wheels (4) are symmetrically arranged on both sides of the plate material (5).

2. A semi-rigid constrained friction additive manufacturing device with high material utilization rate according to claim 1, characterized in that: Also includes a thrust roller bearing (3); The inner ring of the thrust roller bearing (3) is coaxially fixedly sleeved on the rod material (5), and the thrust roller bearing (3) is located between the upper surface of the semi-rigid constraint body (1) and the inner top surface of the temperature-controlled counterweight body (2).

3. A semi-rigid constrained friction additive manufacturing device with high material utilization rate according to claim 1, characterized in that: A central hole (101) penetrating the upper and lower surfaces of the semi-rigid constraint body (1) is provided in the middle of the semi-rigid constraint body (1), and an upper edge chamfer (102) is provided at the edge of the opening of the central hole (101).

4. A semi-rigid constrained friction additive manufacturing device with high material utilization rate according to claim 1, characterized in that: A central stepped hole penetrating the upper and lower surfaces of the temperature-controlling counterweight (2) is provided in the middle of the temperature-controlling counterweight (2), wherein the central stepped hole is composed of a central stepped hole upper portion (201) and a central stepped hole lower portion (202); An annular liquid cooling inner flow channel (203) is provided in the temperature control counterweight body (2), and a cooling medium inlet hole (20301) and a cooling medium outlet hole (20302) which are connected to the liquid cooling inner flow channel (203) are symmetrically provided on the outer wall of the temperature control counterweight body (2).

5. A semi-rigid constrained friction additive manufacturing method with high material utilization, characterized in that: The specific steps include: Step 1, coaxially assemble the semi-rigid constraint body (1), the temperature-controlled counterweight body (2), and the thrust roller bearing (3), and place them at the starting point of the component to be added (6); Step 2, the rod material (5) rotates at a high speed and passes through the central hole (101) of the semi-rigid constraint body (1) under the clamping and feeding action of the feeding wheel (4) to generate heat by friction with the component to be added (6); Step 3: The semi-rigid constraint body (1) forms a radial constraint on the end face of the rod material (5), and combined with the weight of the temperature-controlled counterweight body (2), effectively suppresses the formation of curling, improves material utilization, and forms a dense and well-formed deposition layer (7).

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