Aluminum alloy part and hybrid manufacturing method

Abstract

The application provides an aluminum alloy component and a hybrid manufacturing method, relates to the technical field of hybrid manufacturing, and comprises the following steps: solid-phase additive manufacturing is performed on an aluminum alloy raw material to obtain an additive component; plastic processing treatment is performed on the additive component to obtain the additive component after plastic processing treatment; and heat treatment is performed on the additive component after plastic processing treatment to obtain an aluminum alloy component; in the structure of the solid-phase additive component of the aluminum alloy, the grain size is small, and more grain boundary energy is stored; during solid solution heat treatment, abnormal grain growth is prone to occurring, mm-level grains appear in the structure, and the tensile property is harmed; strain energy is introduced into the additive structure through plastic processing treatment, so that recrystallization nucleation and growth are promoted during heat treatment, and the effect of limiting abnormal grain growth is achieved.

Description

Technical Field

[0001] This invention belongs to the field of manufacturing technology, specifically relating to an aluminum alloy part and a hybrid manufacturing method. Background Technology

[0002] Precipitation-strengthened aluminum alloys (Al-Cu, Al-Mg-Si, Al-Zn, and Al-Li alloys) possess high specific strength, specific stiffness, and fatigue resistance, and are used in structural components in aerospace, automotive, and other fields. Additive manufacturing can produce parts by depositing materials layer by layer. Applying additive manufacturing to the preparation of precipitation-strengthened aluminum alloy components can shorten production cycles and reduce costs. However, the microstructure of precipitation-strengthened aluminum alloys produced by melt additive manufacturing often contains defects such as voids and cracks, making them unsuitable for load-bearing structural components.

[0003] Solid-state additive manufacturing technology, exemplified by triboelectric deposition, allows for the fabrication of dense metal components without melting or solidification during the additive process, and holds promise for applications in the additive manufacturing of precipitation-strengthened aluminum alloys. However, the applicant has discovered at least the following problems when using solid-state additive manufacturing technology to fabricate precipitation-strengthened aluminum alloy components: due to the repeated thermal cycling of the underlying material during the additive process, the precipitated phases become significantly coarser, resulting in a decrease in hardness and strength.

[0004] Existing technologies use solution treatment and aging heat treatment to dissolve the coarsened precipitates and allow them to re-precipitate in a fine, dispersed form. However, because the matrix phase in solid additive structures has fine grains and high grain boundary energy, abnormal grain growth is prone to occur during solution heat treatment, resulting in the alloy's strength after heat treatment not matching the fine-grained structure of the aging state. Summary of the Invention

[0005] Therefore, the present invention provides an aluminum alloy part and a hybrid manufacturing method, which can solve the problem of abnormal grain growth after heat treatment of aluminum alloy solid-phase additive parts in the prior art.

[0006] To address the above problems, the present invention provides a hybrid manufacturing method for aluminum alloy parts, comprising the following steps:

[0007] Steps for preparing additive parts: Solid-state additive manufacturing is performed on aluminum alloy raw materials to obtain additive parts;

[0008] Plastic processing step: The additive part is subjected to plastic processing to obtain the plastic-processed additive part;

[0009] Heat treatment step: The additive part after plastic processing is subjected to heat treatment to obtain a hybrid aluminum alloy part.

[0010] Furthermore, in the step of preparing the additive part: the aluminum alloy raw material is a precipitation-strengthened aluminum alloy rod, including Al-Cu aluminum alloy rods, Al-Mg-Si aluminum alloy rods, Al-Zn aluminum alloy rods, and Al-Li aluminum alloy rods.

[0011] Furthermore, in the plastic processing step: the true strain of the plastic processing is ≥20%, preferably ≥40%, and more preferably 40%~200%; and / or

[0012] The plastic processing is performed by one of rolling, forging, extrusion, and stamping; preferably, the plastic processing is performed by rolling.

[0013] Furthermore, in the step of preparing the additive part: the solid-phase additive manufacturing adopts a triboelectric extrusion deposition method.

[0014] Furthermore, the step of friction extrusion deposition specifically includes: depositing aluminum alloy rod raw material layer by layer onto the surface of a substrate;

[0015] Preferably, the substrate is made of aluminum alloy;

[0016] Preferably, the thickness of the substrate is ≥5mm.

[0017] Furthermore, during the frictional extrusion deposition process, ensure that c·(2~5)·r 2 =v·t·a, and a>2.5r; where t is the thickness of a single additive layer, mm; a is the width of a single additive layer, mm; c is the feed rate of the aluminum alloy raw material, mm / min; v is the travel rate of the friction extrusion deposition die, mm / min; and r is the radius of the aluminum alloy raw material, mm.

[0018] Preferably, the radius of the raw material is 5-20 mm; the rotation speed of the friction extrusion deposition die is 300-600 r / min; the feed rate of the aluminum alloy raw material is 10-500 mm / min; the travel rate of the friction extrusion deposition die is 50-3000 mm / min; the thickness of the single-layer additive layer is 0.5-2 mm; and the width of the single-layer additive layer is 5-60 mm.

[0019] Furthermore, the heat treatment step specifically includes: performing solution treatment and aging treatment sequentially on the additive part after plastic processing.

[0020] Furthermore, the solution treatment temperature is 440-500℃; the holding time is 0.5-4h. Furthermore, the aging treatment includes artificial aging and natural aging.

[0021] The natural aging process takes ≥96 hours.

[0022] The artificial aging treatment is carried out at a temperature of 100-200℃ for 6-48 hours.

[0023] On the other hand, the present invention provides an aluminum alloy part, wherein the grain size of the aluminum alloy part is ≤200μm; nanoscale precipitates are dispersedly distributed within the grains of the aluminum alloy part; wherein the width of the nanoscale precipitates is ≤20nm; the average yield strength of the solid-phase additive aluminum alloy part is ≥300MPa, and the elongation after fracture is ≥8%;

[0024] Preferably, the aluminum alloy part is obtained by any of the above-described hybrid manufacturing methods.

[0025] The aluminum alloy part and its hybrid manufacturing method provided by this invention have the following beneficial effects:

[0026] 1. On the one hand, the microstructure of solid-state additive components based on aluminum alloys has small grain size and stores a lot of grain boundary energy. During solution heat treatment, abnormal grain growth is prone to occur, resulting in millimeter-sized grains in the microstructure, which impairs tensile properties. This invention provides a hybrid manufacturing method for aluminum alloy parts, including the following steps: solid-state additive manufacturing of aluminum alloy raw materials to obtain additive parts; plastic processing of the additive parts to introduce strain energy into the additive parts, and obtaining plastic-processed additive parts; heat treatment of the plastic-processed additive parts to obtain hybrid-manufactured aluminum alloy parts. This invention introduces more strain energy into the additive microstructure through plastic processing, thereby promoting recrystallization nucleation and growth during heat treatment, achieving the effect of limiting abnormal grain growth.

[0027] 2. Furthermore, in the process of friction extrusion deposition, the present invention employs the following formula to ensure good forming of the additive sample, promote tight interlayer interface bonding, thereby ensuring good forming during rolling and effective accumulation of strain energy within the grains, further avoiding abnormal grain growth during heat treatment. The formula is as follows:

[0028] c·(2~5)·r 2 =v·t·a, and a>2.5r; where t is the thickness of the single-layer additive layer, mm; a is the width of the single-layer additive layer, mm; c is the feed rate of the aluminum alloy raw material, mm / min; v is the travel rate of the friction extrusion deposition die, mm / min; and r is the radius of the aluminum alloy raw material, mm.

[0029] 3. On the other hand, the present invention provides an aluminum alloy part, which is obtained by the above-described preparation method, wherein the grain size of the aluminum alloy part is ≤200μm; nanoscale precipitates are dispersedly distributed within the grains of the aluminum alloy part; wherein the width of the nanoscale precipitates is ≤20nm; the average yield strength of the solid-phase additive aluminum alloy part is ≥300MPa, and the elongation after fracture is ≥8%.

[0030] 4. This invention employs friction extrusion deposition additive manufacturing technology in the manufacture of aluminum alloy parts. During the additive process, the material does not melt or solidify, allowing for the creation of dense metal components. This shortens the production cycle and reduces costs. Simultaneously, it avoids the defects such as voids and cracks commonly found in traditional melting additive manufacturing of precipitation-strengthened aluminum alloys. Attached Figure Description

[0031] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the additive manufacturing process for the part prepared in step 1 of Example 1;

[0033] Figure 2 The grain structure of the aluminum alloy part prepared in Example 1;

[0034] Figure 3 The precipitated phase of the aluminum alloy part prepared in Example 1;

[0035] Figure 4 The grain structure of the aluminum alloy part prepared in Example 2;

[0036] Figure 5 The precipitated phase of the aluminum alloy part prepared in Example 2;

[0037] Figure 6 The grain structure of the aluminum alloy part prepared in Example 3;

[0038] Figure 7 The precipitated phase of the aluminum alloy part prepared in Example 3;

[0039] Figure 8 The grain structure of the aluminum alloy part prepared in Comparative Example 1;

[0040] Figure 9 The grain structure of the aluminum alloy part prepared for Comparative Example 2. Detailed Implementation

[0041] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0042] This invention provides a hybrid manufacturing method for aluminum alloy parts, comprising the following steps:

[0043] Steps for preparing additive parts: Solid-state additive manufacturing is performed on Al-Cu-Mg aluminum alloy rods to obtain additive parts;

[0044] The specific steps are as follows: using an aluminum alloy as a substrate, and after surface treatment (surface grinding and cleaning), it is fixed, and then precipitation-strengthened aluminum alloy rods are deposited layer by layer on the surface of the aluminum alloy substrate using a friction extrusion deposition additive manufacturing method.

[0045] The substrate thickness is ≥5mm; during the triboelectric deposition process, ensure c·(2~5)·r 2 =v·t·a, and a>2.5r; where t is the thickness of a single additive layer in mm; a is the width of a single additive layer in mm; c is the feed rate of the aluminum alloy raw material in mm / min; v is the travel rate of the friction extrusion deposition die in mm / min; r is the radius of the aluminum alloy raw material in mm; preferably, the radius of the raw material is 5-20 mm; the rotation speed of the friction extrusion deposition die is 300-600 r / min; the feed rate of the aluminum alloy raw material is 10-500 mm / min; the travel rate of the friction extrusion deposition die is 50-3000 mm / min; the thickness of a single additive layer is 0.5-2 mm; and the width of a single additive layer is 5-60 mm.

[0046] Plastic processing steps: Plastic processing is performed on the additive part to introduce strain energy into the additive part, and the resulting plastic processed additive part is obtained.

[0047] The true strain of the plastic processing is ≥20%, preferably ≥40%, and more preferably 40%~200%. The plastic processing employs one of rolling, forging, extrusion, or stamping. Preferably, the plastic processing is performed by rolling. The true strain, also known as "logarithmic strain," more accurately reflects the actual deformation state of the material during large deformation processes and is obtained by integrating the ratio of instantaneous deformation to instantaneous dimension.

[0048] Heat treatment steps: After plastic processing, the additive part is held at 440-500℃ for 0.5-4h and then quenched to obtain a solution-treated hybrid part. Then, the solution-treated hybrid part is aged to obtain an aluminum alloy part.

[0049] It should be noted that in the microstructure of solid-state additive components made of aluminum alloys, the matrix grains are small, storing a large amount of grain boundary energy, but only a small amount of strain energy, approximately 0.6-1.2 MJ / m³. During solution heat treatment, abnormal grain growth easily occurs, resulting in millimeter-sized grains in the microstructure, which impairs tensile properties. Based on the above method, plastic processing introduces more strain energy into the additive microstructure (the strain energy in the additive part after plastic processing is 1.5-2 times that before plastic processing), thereby promoting recrystallization nucleation and growth during heat treatment, thus limiting the growth of abnormal grains. During plastic processing, a true strain of not less than 20% can effectively suppress abnormal grain growth. In addition, plastic processing can also form a microstructure characterized by high-density, low-angle grain boundaries and high dislocation density within the grains. This microstructure has high intragranular strain energy and a high recrystallization driving force.

[0050] Friction extrusion deposition refers to a process in which raw materials are fed into an inner sleeve, where they rub against a rotating friction extrusion die and soften, and are then extruded to form an additive layer.

[0051] In the aforementioned triboelectric deposition process, aluminum alloy raw material is fed into a triboelectric die, which rotates around its axis and rubs against the raw material, causing localized softening. As the raw material is fed in, the softened material is extruded from the orifice of the triboelectric die. As the die moves forward, the extruded material forms an additive layer on a substrate. After solid-phase additive manufacturing is completed, an additively formed part is obtained.

[0052] Specifically, the friction extrusion deposition die has an opening at the top and an extrusion hole at the bottom. Here, a raw material (aluminum alloy raw material) is fed into the lower end of the friction extrusion die by a feeding mechanism. During the feeding process, the raw material will rub against the inner wall (especially the bottom) of the rotating friction extrusion deposition die, causing the rubbed part of the raw material to soften and be extruded through the extrusion hole.

[0053] In particular, since aluminum alloys have large residual stress during additive manufacturing, the thickness of the substrate must be at least 5mm to avoid warping deformation.

[0054] Due to the poor plasticity of precipitation-strengthened aluminum alloys, forming during additive manufacturing is difficult and prone to defects such as pores and cracks. Therefore, ensuring c·(2~5)·r during the friction extrusion deposition process is crucial. 2 =v·t·a, and a>2.5r. At this point, the temperature and flowability of the extruded material during additive manufacturing can be controlled, thereby ensuring the formability of Al-Cu-Mg aluminum alloys and ensuring an appropriate material extrusion amount (if the extrusion amount is too large, it will lead to excessive frictional heat and plastic deformation heat, resulting in defects such as holes and peeling on the surface of the additive layer; if the extrusion amount is too small, it will lead to material shortage and the formation of an incomplete additive layer), thereby avoiding the generation of macroscopic defects.

[0055] Furthermore, this formula allows for control of heat input during the additive manufacturing process, as well as the shaping process itself. Controlling heat input prevents excessively small grain sizes in the additive structure. When grain sizes are too small, the stored grain boundary energy is high, and strain is difficult to accumulate within the grains, leading to a decrease in the effectiveness of plastic deformation in inhibiting abnormal grain growth. If the rotation speed of the triboelectric deposition die is too high, excessive heat generation will occur, resulting in defects such as peeling and voids on the additive layer surface. If the rotation speed of the triboelectric deposition die is too low, the temperature will be too low, resulting in insufficient material flowability and poor forming.

[0056] In some embodiments, prior to the plastic forming process, the process further includes: removing unbonded areas at the edges of the additive part to avoid defects during plastic forming; and after aging treatment, removing the substrate and / or excess material from the additive part.

[0057] When precipitation-strengthened aluminum alloys are heated, the precipitated phases coarsen, leading to a weakening of the strengthening effect and a decrease in hardness and strength. Consequently, the previous additive layer softens due to heating by subsequent additive layers, resulting in reduced strength. The purpose of heat treatment is to eliminate this adverse effect and restore strength. Heat treatment dissolves these coarsened strengthening phases (solution treatment) and allows them to reprecipitate in a fine, dispersed form (aging treatment). The selection of the temperature and time for the solution treatment ensures that the precipitated phases in the aluminum alloy are fully dissolved without localized liquefaction (overheating). The aging treatment time is to ensure the full formation of nanoscale precipitates.

[0058] The above method is explained below:

[0059] 1) In the above steps of this invention, strain energy is introduced into the additive structure by performing plastic processing on the additive part. This promotes recrystallization nucleation and growth in the additive structure and inhibits abnormal grain growth during heat treatment.

[0060] 2) In the above steps of this invention, the solid-phase additive manufacturing technology such as friction extrusion deposition process is used. During the additive manufacturing process, the raw materials do not undergo melting and solidification, and the temperature is relatively low, which avoids the defects that may occur in melting additive manufacturing and is suitable for additive manufacturing of aluminum alloy materials.

[0061] On the other hand, the present invention provides an aluminum alloy part, which is obtained by any of the above preparation methods; the grain size of the aluminum alloy part is ≤200μm; nanoscale precipitates are dispersedly distributed in the grains of the aluminum alloy part; wherein the width of the nanoscale precipitates is ≤20nm; the average yield strength of the solid-phase additive aluminum alloy part is ≥300MPa, and the elongation after fracture is ≥8%.

[0062] The present invention will be further described below with reference to specific embodiments and comparative examples.

[0063] Example 1

[0064] This embodiment provides a hybrid manufacturing method for aluminum alloy parts, including the following steps:

[0065] Additive part preparation steps: Grind and clean an 8mm thick aluminum alloy substrate and clamp it on the worktable; then feed a 2219 aluminum alloy rod into a friction extrusion die. The friction extrusion die rotates around its axis and rubs against the raw material, causing the raw material to soften locally. As the raw material is fed in, the softened material is extruded from the orifice of the friction extrusion die. As the die moves forward, the extruded material forms an additive layer on the substrate. After the friction extrusion deposition is completed, the additive part is obtained.

[0066] In the triboelectric deposition process, the radius r of the aluminum alloy rod is 10 mm, the rotational speed of the triboelectric deposition die is 300 r / min, the feed rate c of the aluminum alloy rod is 10 mm / min, the thickness t of the single-layer additive layer is 1 mm, the width a of the single-layer additive layer is 26 mm, and the travel speed v of the triboelectric deposition die is 100 mm / min; the above parameters satisfy: c·(2~5)·r 2 =v·t·a and a>2.5r.

[0067] Plastic processing steps: The above-mentioned additive parts are subjected to plastic processing to introduce strain energy into the additive parts, and the resulting plastic-processed additive parts are obtained; wherein, the true strain of the plastic processing is 22%; the plastic processing is carried out by rolling.

[0068] Heat treatment steps: After plastic processing, the additive part is held at 500℃ for 1 hour and then quenched to obtain a solution-treated hybrid part; then, the solution-treated hybrid part is artificially aged at 200℃ for 6 hours; finally, the excess material is removed to obtain the aluminum alloy part.

[0069] Figure 1 This is a schematic diagram of the additive manufacturing process for the part prepared in step 1 of Example 1. The process includes feeding raw material 1 into the inner sleeve 2, where it rubs against and softens against the rotating die 3, and is then extruded to form an additive layer 4. Observing the aluminum alloy part prepared in this example, it can be seen that the additive manufacturing process produces good results without defects such as holes or cracks. Figure 2 The grain structure of the aluminum alloy part prepared in this embodiment shows that the average grain size is about 180 μm. Figure 3 The precipitates in the aluminum alloy part prepared in this embodiment show that nano-sized precipitates are dispersed within the grains, with the size of the nano-sized precipitates not exceeding 20 nm. The solid-phase additive aluminum alloy part prepared in this embodiment has an average yield strength of 367 MPa and an elongation after fracture of 10%.

[0070] Example 2

[0071] This embodiment provides a hybrid manufacturing method for aluminum alloy parts, including the following steps:

[0072] Additive part preparation steps: Grind and clean a 5mm thick aluminum alloy substrate and clamp it on the worktable; then feed a 2195 aluminum alloy rod into the friction extrusion die. The friction extrusion die rotates around its axis and rubs against the raw material, causing the raw material to soften locally. As the raw material is fed, the softened material is extruded from the orifice of the friction extrusion die. As the die moves forward, the extruded material forms an additive layer on the substrate. After the friction extrusion deposition is completed, the additive part is obtained.

[0073] In the triboelectric deposition process, the radius r of the alloy rod is 20 mm, the rotational speed of the triboelectric deposition die is 600 r / min, the feed rate c of the aluminum alloy rod is 10 mm / min, the thickness t of the single-layer additive layer is 0.5 mm, the width a of the single-layer additive layer is 60 mm, and the travel speed v of the triboelectric deposition die is 330 mm / min; the above parameters satisfy: c·(2~5)·r 2 =v·t·a and a>2.5r.

[0074] Plastic processing steps: The above-mentioned additive parts are subjected to plastic processing to introduce strain energy into the additive parts, and the resulting plastic-processed additive parts are obtained; wherein, the true strain of the plastic processing is 51%; the plastic processing is carried out by rolling.

[0075] Heat treatment steps: After plastic processing, the additive part is held at 500℃ for 0.5h and then quenched to obtain a solution-treated hybrid part; then, the solution-treated hybrid part is artificially aged at 170℃ for 10h; finally, the excess material is removed to obtain the aluminum alloy part.

[0076] Observing the aluminum alloy parts prepared in this embodiment, it can be seen that the additive manufacturing process produces good results without defects such as holes or cracks. Figure 4 The grain structure of the aluminum alloy part prepared in this embodiment shows that the average grain size is about 28 μm. Figure 5 The precipitates in the aluminum alloy part prepared in this embodiment show that nanoscale precipitates are dispersed within the grains, with the size of the nanoscale precipitates not exceeding 20 nm. The solid-phase additive aluminum alloy part prepared in this embodiment has an average yield strength of 351 MPa and an elongation after fracture of 11%.

[0077] Example 3

[0078] This embodiment provides a hybrid manufacturing method for aluminum alloy parts, including the following steps:

[0079] Additive part preparation steps: Grind and clean a 5mm thick aluminum alloy substrate and clamp it on the worktable; then feed a 7075 aluminum alloy rod into the friction extrusion die. The friction extrusion die rotates around its axis and rubs against the raw material, causing the raw material to soften locally. As the raw material is fed, the softened material is extruded from the orifice of the friction extrusion die. As the die moves forward, the extruded material forms an additive layer on the substrate. After the friction extrusion deposition is completed, the additive part is obtained.

[0080] In the triboelectric deposition process, the radius r of the aluminum alloy rod is 5 mm, the rotational speed of the triboelectric deposition die is 300 r / min, the feed rate c of the aluminum alloy rod is 500 mm / min, the thickness t of the single-layer additive layer is 2 mm, the width a of the single-layer additive layer is 30 mm, and the travel speed v of the triboelectric deposition die is 500 mm / min; the above parameters satisfy: c·(2~5)·r 2 =v·t·a and a>2.5r.

[0081] Plastic processing steps: The above additive parts are subjected to plastic processing to introduce strain energy into the additive parts, and the resulting plastic-processed additive parts are obtained; wherein, the true strain of the plastic processing is 161%; the plastic processing is carried out by rolling.

[0082] Heat treatment steps: After plastic processing, the additive part is held at 440℃ for 4 hours and then quenched to obtain a solution-treated hybrid part; then, the solution-treated hybrid part is artificially aged at 100℃ for 48 hours; finally, the excess material is removed to obtain the aluminum alloy part.

[0083] Observing the aluminum alloy parts prepared in this embodiment, it can be seen that the additive manufacturing process produces good results without defects such as holes or cracks. Figure 6 The grain structure of the aluminum alloy part prepared in this embodiment shows that the average grain size is about 5 μm. Figure 7 The precipitates in the aluminum alloy part prepared in this embodiment show that nano-sized precipitates are dispersed within the grains, with the size of the nano-sized precipitates not exceeding 20 nm. The solid-phase additive aluminum alloy part prepared in this embodiment has an average yield strength of 503 MPa and an elongation after fracture of 9%.

[0084] Example 4

[0085] This embodiment provides a hybrid manufacturing method for aluminum alloy parts, including the following steps:

[0086] Additive part preparation steps: Grind and clean a 5mm thick aluminum alloy substrate and clamp it on the worktable; then feed a 2024 aluminum alloy rod into the friction extrusion die. The friction extrusion die rotates around its axis and rubs against the raw material, causing the raw material to soften locally. As the raw material is fed, the softened material is extruded from the orifice of the friction extrusion die. As the die moves forward, the extruded material forms an additive layer on the substrate. After the friction extrusion deposition is completed, the additive part is obtained.

[0087] In the triboelectric deposition process, the radius r of the aluminum alloy rod is 5 mm, the rotational speed of the triboelectric deposition die is 300 r / min, the feed rate c of the aluminum alloy rod is 500 mm / min, the thickness t of the single-layer additive layer is 2 mm, the width a of the single-layer additive layer is 30 mm, and the travel speed v of the triboelectric deposition die is 500 mm / min; the above parameters satisfy: c·(2~5)·r 2 =v·t·a and a>2.5r.

[0088] Plastic processing steps: The above additive parts are subjected to plastic processing to introduce strain energy into the additive parts, and the resulting plastic-processed additive parts are obtained; wherein, the true strain of the plastic processing is 161%; the plastic processing is carried out by rolling.

[0089] Heat treatment steps: After plastic processing, the additive part is held at 500℃ for 4 hours and then quenched to obtain a solution-treated hybrid part; then, the solution-treated hybrid part is naturally aged for 96 hours; finally, the excess material is removed to obtain the aluminum alloy part.

[0090] The solid-phase additive aluminum alloy parts prepared in this embodiment have an average yield strength of 323 MPa and an elongation after fracture of 19%.

[0091] Comparative Example 1

[0092] This comparative example provides a hybrid manufacturing method for aluminum alloy parts, including the following steps:

[0093] Additive part preparation steps: Grind and clean an 8mm thick aluminum alloy substrate and clamp it on the worktable; then feed a 2024 aluminum alloy rod into the friction extrusion die. The friction extrusion die rotates around its axis and rubs against the raw material, causing the raw material to soften locally. As the raw material is fed, the softened material is extruded from the orifice of the friction extrusion die. As the die moves forward, the extruded material forms an additive layer on the substrate. After the friction extrusion deposition is completed, the additive part is obtained.

[0094] In the triboelectric deposition process, the radius r of the aluminum alloy rod is 10 mm, the rotational speed of the triboelectric deposition die is 300 r / min, the feed rate c of the aluminum alloy rod is 10 mm / min, the thickness t of the single-layer additive layer is 1 mm, the width a of the single-layer additive layer is 26 mm, and the travel speed v of the triboelectric deposition die is 100 mm / min; the above parameters satisfy: c·(2~5)·r 2 =v·t·a and a>2.5r.

[0095] Heat treatment steps: After plastic processing, the additive part is held at 500℃ for 1 hour and then quenched to obtain a solution-treated hybrid part; then, the solution-treated hybrid part is naturally aged for 96 hours; finally, the excess material is removed to obtain the aluminum alloy part.

[0096] Figure 8 The microstructure of the aluminum alloy part prepared in this comparative example shows that the average grain size is approximately 1300 μm. The average yield strength of the solid-state additive aluminum alloy part prepared in this comparative example is 287 MPa, and the elongation after fracture is 18%. Due to the small grain size of the additive part, a large amount of grain boundary energy is stored in the microstructure. Therefore, during solution heat treatment, under the influence of the driving force of reduced grain boundary energy, severe abnormal grain growth occurs in the microstructure, resulting in millimeter-scale grain size.

[0097] Comparative Example 2

[0098] This comparative example provides a hybrid manufacturing method for aluminum alloy parts, including the following steps:

[0099] Additive part preparation steps: Grind and clean an 8mm thick aluminum alloy substrate and clamp it on the worktable; then feed a 2024 aluminum alloy rod into the friction extrusion die. The friction extrusion die rotates around its axis and rubs against the raw material, causing the raw material to soften locally. As the raw material is fed, the softened material is extruded from the orifice of the friction extrusion die. As the die moves forward, the extruded material forms an additive layer on the substrate. After the friction extrusion deposition is completed, the additive part is obtained.

[0100] In the triboelectric deposition process, the radius r of the aluminum alloy rod is 10 mm, the rotational speed of the triboelectric deposition die is 300 r / min, the feed rate c of the aluminum alloy rod is 10 mm / min, the thickness t of the single-layer additive layer is 1 mm, the width a of the single-layer additive layer is 26 mm, and the travel speed v of the triboelectric deposition die is 100 mm / min; the above parameters satisfy: c·(2~5)·r 2 =v·t·a and a>2.5r.

[0101] Plastic processing steps: The above additive parts are subjected to plastic processing to introduce strain energy into the additive parts, and the resulting plastic-processed additive parts are obtained; wherein, the true strain of the plastic processing is 11%; the plastic processing is carried out by rolling.

[0102] Heat treatment steps: After plastic processing, the additive part is held at 500℃ for 1 hour and then quenched to obtain a solution-treated hybrid part; then, the solution-treated hybrid part is naturally aged for 96 hours; finally, the excess material is removed to obtain the aluminum alloy part.

[0103] Figure 9 The microstructure of the aluminum alloy part prepared in this comparative example shows that the average grain size is approximately 580 μm. The average yield strength of the solid-phase additive aluminum alloy part prepared in this comparative example is 294 MPa, and the elongation after fracture is 19%. Due to the small true strain of the plastic processing in Comparative Example 2, insufficient strain energy is introduced into the microstructure, making it difficult to suppress abnormal grain growth during heat treatment.

[0104] Comparative Example 3

[0105] This comparative example provides a hybrid manufacturing method for aluminum alloy parts, including the following steps:

[0106] The 8mm thick aluminum alloy substrate is polished and cleaned, and then clamped on the worktable. The 2219 aluminum alloy rod is then fed into the friction extrusion die. The friction extrusion die rotates around its axis and rubs against the raw material, causing the raw material to soften locally. As the raw material is fed, the softened material is extruded from the orifice of the friction extrusion die. As the die moves forward, the extruded material forms an additive layer on the substrate. After the friction extrusion deposition is completed, the additive part is obtained.

[0107] In the triboelectric deposition process, the radius r of the aluminum alloy rod is 10 mm, the rotational speed of the triboelectric deposition die is 275 r / min, the feed rate c of the aluminum alloy rod is 10 mm / min, the thickness t of the single-layer additive layer is 1 mm, the width a of the single-layer additive layer is 26 mm, and the travel speed v of the triboelectric deposition die is 100 mm / min; the above parameters satisfy: c·(2~5)·r 2 =v·t·a and a>2.5r.

[0108] Observing the aluminum alloy parts prepared in this comparative example, it can be seen that excessively low rotation speed leads to reduced heat input, insufficient material plasticity, decreased formability, and the appearance of voids in the additive layer. Furthermore, the grain size of the additive structure will decrease due to reduced heat input. This smaller grain size makes it difficult to effectively accumulate strain energy within the grains, thus hindering the effective suppression of abnormal grain growth. Moreover, the smaller grain size stores higher grain boundary energy, resulting in a greater driving force for abnormal grain growth, thereby promoting abnormal grain growth.

[0109] Comparative Example 4

[0110] This comparative example provides a hybrid manufacturing method for aluminum alloy parts, including the following steps:

[0111] The 8mm thick aluminum alloy substrate is polished and cleaned, and then clamped on the worktable. The 2219 aluminum alloy rod is then fed into the friction extrusion die. The friction extrusion die rotates around its axis and rubs against the raw material, causing the raw material to soften locally. As the raw material is fed, the softened material is extruded from the orifice of the friction extrusion die. As the die moves forward, the extruded material forms an additive layer on the substrate. After the friction extrusion deposition is completed, the additive part is obtained.

[0112] In the triboelectric deposition process, the radius r of the aluminum alloy rod is 10 mm, the rotational speed of the triboelectric deposition die is 700 r / min, the feed rate c of the aluminum alloy rod is 10 mm / min, the thickness t of the single-layer additive layer is 1 mm, the width a of the single-layer additive layer is 26 mm, and the travel speed v of the triboelectric deposition die is 100 mm / min; the above parameters satisfy: c·(2~5)·r 2 =v·t·a and a>2.5r.

[0113] Observation of the aluminum alloy parts prepared in this comparative example shows that due to the excessively high rotation speed of the friction extrusion deposition die, the friction between the die and the additive layer is too intense, resulting in defects on the surface of the additive layer. Furthermore, excessive heat generation in the material leads to excessively large grain size.

[0114] Comparative Example 5

[0115] This comparative example provides a hybrid manufacturing method for aluminum alloy parts, including the following steps:

[0116] The 8mm thick aluminum alloy substrate is polished and cleaned, and then clamped on the worktable. The 2219 aluminum alloy rod is then fed into the friction extrusion die. The friction extrusion die rotates around its axis and rubs against the raw material, causing the raw material to soften locally. As the raw material is fed, the softened material is extruded from the orifice of the friction extrusion die. As the die moves forward, the extruded material forms an additive layer on the substrate. After the friction extrusion deposition is completed, the additive part is obtained.

[0117] In the triboelectric deposition process, the radius r of the aluminum alloy rod is 10 mm, the rotational speed of the triboelectric deposition die is 300 r / min, the feed rate c of the aluminum alloy rod is 10 mm / min, the thickness t of the single-layer additive layer is 1 mm, the width a of the single-layer additive layer is 26 mm, and the travel speed v of the triboelectric deposition die is 200 mm / min. The above parameters do not satisfy: c·(2~5)·r 2 =v·t·a and a>2.5r.

[0118] Observing the aluminum alloy parts prepared in this comparative example, it can be seen that the parameters of the friction extrusion deposition do not satisfy c·(2~5)·r 2 =v·t·a, resulting in insufficient additive layer material and the appearance of voids. Furthermore, the presence of void defects can easily lead to abnormal grain growth due to surface energy.

[0119] Comparative Example 6

[0120] This comparative example provides a hybrid manufacturing method for aluminum alloy parts, including the following steps:

[0121] Additive part preparation steps: Grind and clean an 8mm thick aluminum alloy substrate and clamp it on the worktable; then feed a 2219 aluminum alloy rod into a friction extrusion die. The friction extrusion die rotates around its axis and rubs against the raw material, causing the raw material to soften locally. As the raw material is fed in, the softened material is extruded from the orifice of the friction extrusion die. As the die moves forward, the extruded material forms an additive layer on the substrate. After the friction extrusion deposition is completed, the additive part is obtained.

[0122] In the triboelectric deposition process, the radius r of the aluminum alloy rod is 10 mm, the rotational speed of the triboelectric deposition die is 300 r / min, the feed rate c of the aluminum alloy rod is 10 mm / min, the thickness t of the single-layer additive layer is 1 mm, the width a of the single-layer additive layer is 26 mm, and the travel speed v of the triboelectric deposition die is 100 mm / min; the above parameters satisfy: c·(2~5)·r 2 =v·t·a and a>2.5r.

[0123] Plastic processing steps: The above-mentioned additive parts are subjected to plastic processing to introduce strain energy into the additive parts, and the resulting plastic-processed additive parts are obtained; wherein, the true strain of the plastic processing is 22%; the plastic processing is carried out by rolling.

[0124] Heat treatment steps: After plastic processing, the additive part is held at 510℃ for 4 hours and then quenched to obtain a solution-treated hybrid part; then, the solution-treated hybrid part is artificially aged at 200℃ for 6 hours; finally, the excess material is removed to obtain the aluminum alloy part.

[0125] Because the solution treatment temperature is too high, it is easy to promote the growth of abnormal grains and cause overheating defects in the microstructure. The average yield strength of the solid additive aluminum alloy part prepared in this embodiment is only 276 MPa and the elongation after fracture is 6%.

[0126] It will be readily understood by those skilled in the art that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0127] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A hybrid manufacturing method for aluminum alloy parts, characterized in that, Includes the following steps: Steps for preparing additive parts: Solid-state additive manufacturing is performed on aluminum alloy raw materials to obtain additive parts; The solid-phase additive manufacturing process employs triboelectric extrusion deposition, ensuring that c·(2~5)·r during the triboelectric extrusion deposition process... 2 =v·t·a, and a>2.5r; where t is the thickness of the single-layer additive layer, mm; a is the width of the single-layer additive layer, mm; c is the feed rate of the aluminum alloy raw material, mm / min; v is the travel rate of the friction extrusion deposition die, mm / min; and r is the radius of the aluminum alloy raw material, mm. Plastic processing step: The additive part is subjected to plastic processing with a true strain of 40%~200% to obtain the plastic processed additive part; Heat treatment step: The additive part after plastic processing is subjected to heat treatment to obtain a hybrid aluminum alloy part; wherein, The heat treatment steps specifically include: performing solution treatment and aging treatment on the additive parts after plastic processing in sequence; the solution treatment temperature is 440-500℃; and the holding time is 0.5-4h.

2. The method for hybrid manufacturing of aluminum alloy parts according to claim 1, characterized in that, In the step of preparing the additive part: The aluminum alloy raw material is a precipitation-strengthened aluminum alloy rod.

3. The method for hybrid manufacturing of aluminum alloy parts according to claim 1, characterized in that, In the plastic processing step: The plastic forming process employs one of the following methods: rolling, forging, extrusion, or stamping.

4. The method for hybrid manufacturing of aluminum alloy parts according to claim 1, characterized in that, The specific steps of the friction extrusion deposition include: depositing aluminum alloy rod raw material layer by layer onto the surface of a substrate; The substrate is made of aluminum alloy; the thickness of the substrate is ≥5mm.

5. The method for hybrid manufacturing of aluminum alloy parts according to claim 1, characterized in that, The radius of the aluminum alloy raw material is 5-20mm; the rotation speed of the friction extrusion deposition die is 300-600r / min; the feed rate of the aluminum alloy raw material is 10-500mm / min; the travel rate of the friction extrusion deposition die is 50-3000mm / min; the thickness of a single additive layer is 0.5-2mm; and the width of a single additive layer is 5-60mm.

6. The method for hybrid manufacturing of aluminum alloy parts according to claim 1, characterized in that, The aging treatment is performed at a temperature of 100-200℃ for 6-48 hours.

7. An aluminum alloy part, characterized in that, The aluminum alloy part has a grain size ≤200μm; nanoscale precipitates are dispersed within the grains of the aluminum alloy part; wherein the width of the nanoscale precipitates is ≤20nm; the average yield strength of the aluminum alloy part is ≥300MPa, and the elongation after fracture is ≥8%; The aluminum alloy part is obtained by the hybrid manufacturing method described in any one of claims 1-6.

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