Additive forging composite forming method for integrally loading local deformation on aluminum alloy lightweight wheel-shaped component

Abstract

The invention discloses an additive forging composite forming method for integrally loading local deformation on an aluminum alloy lightweight wheel-shaped component, and relates to an additive forging composite forming method for a wheel-shaped component. The problems that an existing spaceflight aluminum alloy light-weight wheel-shaped component is poor in direct additive forming structure performance, a forging forming die is difficult to fill, the forging process is long, and the die cost is high are solved. The method comprises the following steps: 1, performing additive forming on a main blank; 2, pre-forging and forming the spoke; 3, machining and finishing the pre-forged piece; fourthly, secondary material adding is conducted on the rim; 5, carrying out homogenization heat treatment on the whole wheel; 6, integrally forging and forming the wheel; and 7, wheel direct aging strengthening treatment. The method is used for additive forging composite forming of the aluminum alloy light-weight wheel-shaped component subjected to overall loading and local deformation.

Description

Technical Field

[0001] The invention relates to an additive forging composite forming method for a wheel-shaped component. Background Art

[0002] As my country's exploration of deep space such as the moon and Mars continues to deepen, higher requirements for high performance, low weight and mission diversification have been put forward for the new generation of manned lunar rovers, Mars rovers and other spacecraft. Among them, wheel components, as one of the main motion and load-bearing components, are developing in the direction of high performance, single-piece personalization, extreme lightweight and integration of complex structural components. Therefore, the production and preparation process of lightweight wheel-shaped components in the aerospace field should have the characteristics of single-piece or small-batch rapid manufacturing, short production cycle, and fast replacement, which poses a huge challenge to processing and manufacturing technology. High-strength aluminum alloys have the advantages of high specific strength, low density, good formability, and excellent corrosion resistance. They are very suitable as materials for lightweight components and are currently widely used in the aerospace field.

[0003] Due to the demand for extremely lightweight wheel-shaped components in the aerospace field, the structural complexity of the components is very high. Lightweight wheel-shaped components are composed of thin-walled rims with reinforced structures and spokes with complex topological hollow shapes. The topological spokes are the main supporting parts, responsible for supporting the force of the entire wheel; the thin-walled rims are assembled with the outer tires, responsible for bearing the impact loads transmitted by the tires; the spoke assembly flanges are assembled with the axles and steering mechanisms, responsible for transmitting the driving force and steering torque, etc. Therefore, the above parts have extremely high requirements for the mechanical properties of the components, and require the components to be formed as an integrated whole.

[0004] However, traditional processing technology is difficult to meet the manufacturing needs of new lightweight and complex wheel-shaped components in the aerospace field. The forging method of forging blanks is difficult to fill the wheel rim height fully, and multiple sets of pre-forging dies are required. The blank making is complicated, the mold cost is high, and the manufacturing cycle is long. The emerging arc additive manufacturing technology can quickly form complex components. It has the advantages of flexible materials, high manufacturing flexibility, fast forming speed, and low single-piece or small-batch manufacturing costs. It is very suitable for processing large-scale integral components with large duty cycle and complex structures such as lightweight wheel-shaped components. However, arc additive components have poor deposited microstructure performance and are sensitive to pore defects, making it difficult to meet the high standards of spacecraft.

[0005] Therefore, a new forming method is urgently needed to achieve rapid overall forming of lightweight wheel-shaped components made of aluminum alloy in the aerospace field, while ensuring that the organizational properties of the assembly areas and transition areas of the wheel spokes and rims of the wheel-shaped components are excellent and stable. Summary of the invention

[0006] The present invention aims to solve the problems of poor microstructure and performance of existing aerospace aluminum alloy lightweight wheel-shaped components through direct additive forming, difficulty in filling forging forming dies, long forging process and high die cost, and further provide an additive forging composite forming method for overall loading and local deformation of aluminum alloy lightweight wheel-shaped components.

[0007] An additive forging composite forming method for an aluminum alloy lightweight wheel-shaped component with overall loading and local deformation is carried out in the following steps:

[0008] 1. Additive forming of main blank:

[0009] The wheel body is formed by using an arc wire feeding additive manufacturing method, and then the surface of the wheel body is polished and smoothed to obtain a wheel additive blank;

[0010] The wheel additive blank is formed by connecting a wheel rim and a wheel spoke;

[0011] 2. Spoke pre-forging and forming:

[0012] The wheel additive blank and the forging die are lubricated, and then the wheel additive blank is heated to the aluminum alloy forging temperature T1 and kept warm, and the forging die is preheated to the temperature T2, and then the wheel additive blank is placed in the forging die and positioned, and the spokes of the wheel additive blank are pre-forged at a pressing speed of 2.5 mm / s to 12.8 mm / s, and finally cooled to room temperature in air, and the flash is removed to obtain a wheel pre-forged part;

[0013] 3. Machining and finishing of pre-forgings:

[0014] The upper and lower end surfaces of the wheel rim of the wheel preforging are processed to be flat, and the oxide layers on the inner and outer surfaces of the wheel rim are polished off to obtain a trimmed preforging;

[0015] 4. Secondary material addition of wheel rims:

[0016] Using an arc wire feeding additive manufacturing method, secondary additive forming is performed on the upper and lower end faces of the rim and the inner and outer surfaces of the rim in the trimmed pre-forged part, and then polished to obtain a secondary additive wheel;

[0017] 5. Overall uniform heat treatment of wheels:

[0018] At temperature T3, the secondary additive wheel is subjected to homogenization heat treatment for 8 hours to 24 hours, and finally cooled to room temperature in air to obtain a homogenized secondary additive wheel;

[0019] 6. Overall forging of wheels:

[0020] The homogenized secondary additive wheel and the forging die are lubricated, and then the homogenized secondary additive wheel is heated to the aluminum alloy forging temperature T4 and kept warm, and the forging die is preheated to the temperature T5, and then the homogenized secondary additive wheel is placed in the forging die and positioned, and the homogenized secondary additive wheel is forged as a whole at a pressing speed of 2.5 mm / s to 12.8 mm / s, and finally quickly cooled to room temperature, and the flash is removed to obtain the wheel final forging;

[0021] 7. Direct aging strengthening treatment of wheels:

[0022] The wheel final forging is subjected to artificial aging strengthening treatment and then cooled to room temperature in air, thereby completing the additive forging composite forming method of the aluminum alloy lightweight wheel-shaped component with overall loading and local deformation.

[0023] The beneficial effects of the present invention are:

[0024] The present invention provides an additive forging composite forming method for an aluminum alloy lightweight wheel-shaped component with overall loading and local deformation, comprising: preparing a wheel additive blank by adopting an arc additive manufacturing method, performing a spoke pre-forging forming process with a total required reduction of 40% to 60% on the wheel additive blank in a mold, removing flash and performing surface finishing, then performing secondary additive at the rim of the pre-forged component to supplement the material, performing overall homogenization treatment on the secondary additive wheel, and then performing overall forging forming in the same mold to obtain a wheel final forging that is fully filled, free of defects such as cracks and pores, and has qualified shape and size, and finally performing artificial aging strengthening treatment to obtain a wheel part that meets the requirements in terms of final mechanical properties and shape and size.

[0025] The present invention prepares a billet with a certain complex structure shape through an arc wire feeding additive manufacturing method, replacing the traditional multiple billet making process, shortening the manufacturing process and saving mold costs and forging billet costs, while improving material utilization. After the additive billet is pre-forged and formed, secondary additive filling is performed on the rim part, and then the overall forging is performed, which ensures that the die cavity of the higher rim part of the forging is filled completely, and solves the problem of insufficient filling of the high-rib deep cavity part with a large aspect ratio in the traditional one-step forging forming; at the same time, the secondary additive filling method improves the forging flexibility, and the same set of forging dies are used for the two forgings of pre-forging and overall forging, which greatly saves the mold manufacturing cost.

[0026] The present invention is formed by two forgings, namely, pre-forging and integral forging, wherein the metal volume of the spoke part of the additive blank is larger than that of the spoke part of the final forging, and its excess metal flows into the flash during the two forging processes, thereby ensuring that the deformation of the spoke part is sufficient and preventing the thinner spoke part from becoming unstable during the forging process; the rim part of the additive blank undergoes a certain amount of deformation during the pre-forging process, and the integral forging after the secondary additive process further increases the overall deformation of the rim, thereby ensuring that the deformation of the rim part is sufficient; the sufficient deformation of the arc additive blank enables the defects of additive pores, cracks and unfused materials to be fully forged, thereby reducing the brittleness of the additive component and improving the fatigue performance, while significantly improving the additive layered structure, reducing the anisotropy of the mechanical properties of the additive component, and solving the problems of large residual stress, sensitive pore defects, poor structure and mechanical properties of directly additive wheel components.

[0027] The present invention improves the uniformity of the microstructure and performance of the additive component by performing overall homogenization heat treatment after the secondary additive process, while narrowing the microstructure and performance gap between the pre-forged part and the secondary additive part, improving the deformation coordination of the two parts during the subsequent overall forging process, and effectively preventing the forging filling difficulties and the uneven microstructure and performance of the final forging caused by uneven deformation. In addition, the additive-forging interface between the pre-forged part and the secondary additive part generates sufficient flow during the subsequent overall forging process, which can significantly eliminate defects such as poor fusion at the interface, improve the interface structure, and increase the interface bonding strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram of the one-step forging process of a wheel-shaped component in a comparative experiment using the traditional process, a is before forging, A is the upper die, B is the wheel forging blank, C is the lower die, b is after forging, and D is the unfilled part;

[0030] Figure 2 This is a schematic diagram of the structure of the wheel additive blank prepared in step 1 of Example 1;

[0031] Figure 3 Schematic diagram of the die cavity of the forging die used in step 2 and step 6 of Example 1, a is the upper die, b is the lower die, and c is a schematic diagram of the longitudinal section of the die cavity in the closed state of the die;

[0032] Figure 4 : The finite element simulation results of the spoke pre-forging forming process in step 2 of Example 1, a is a schematic diagram of a wheel pre-forging without removing the flash, and b is a local strain cloud diagram of the wheel pre-forging;

[0033] Figure 5 This is a schematic diagram of the trimmed pre-forged part prepared in step 3 of Example 1;

[0034] Figure 6 Schematic diagram of a secondary material addition wheel prepared in step 4 of Example 1, where A is the secondary material addition position on the upper and lower end surfaces of the wheel rim;

[0035] Figure 7 : The finite element simulation result of the integral forging process of the wheel in step 6 of the first embodiment, a is the final wheel forging without removing the flash, and b is the local strain cloud diagram of the final wheel forging;

[0036] Figure 8 This is a schematic diagram of the structure of the wheel final forging prepared in step six of Example 1;

[0037] Fig. 9 The microstructure comparison diagram of the final forgings after aging prepared in Example 1 and Comparative Experiment 2, a is Comparative Experiment 2, and b is Example 1;

[0038] Fig.10 The defect conditions of the final forgings after aging prepared in Example 1 and Comparative Experiment 2 are compared, a is Comparative Experiment 2, and b is Example 1;

[0039] Fig.11 The room temperature mechanical properties of the final forgings after aging prepared in Example 1 and Comparative Experiment 2 are compared, A is Comparative Experiment 2, and B is Example 1. DETAILED DESCRIPTION

[0040] Specific implementation method 1: This implementation method is an additive forging composite forming method for an aluminum alloy lightweight wheel-shaped component with overall loading and local deformation, which is carried out in the following steps:

[0041] 1. Additive forming of main blank:

[0042] The wheel body is formed by using an arc wire feeding additive manufacturing method, and then the surface of the wheel body is polished and smoothed to obtain a wheel additive blank;

[0043] The wheel additive blank is formed by connecting a wheel rim and a wheel spoke;

[0044] 2. Spoke pre-forging and forming:

[0045] The wheel additive blank and the forging die are lubricated, and then the wheel additive blank is heated to the aluminum alloy forging temperature T1 and kept warm, and the forging die is preheated to the temperature T2, and then the wheel additive blank is placed in the forging die and positioned, and the spokes of the wheel additive blank are pre-forged at a pressing speed of 2.5 mm / s to 12.8 mm / s, and finally cooled to room temperature in air, and the flash is removed to obtain a wheel pre-forged part;

[0046] 3. Machining and finishing of pre-forgings:

[0047] The upper and lower end surfaces of the wheel rim of the wheel preforging are processed to be flat, and the oxide layers on the inner and outer surfaces of the wheel rim are polished off to obtain a trimmed preforging;

[0048] 4. Secondary material addition of wheel rims:

[0049] Using an arc wire feeding additive manufacturing method, secondary additive forming is performed on the upper and lower end faces of the rim and the inner and outer surfaces of the rim in the trimmed pre-forged part, and then polished to obtain a secondary additive wheel;

[0050] 5. Overall uniform heat treatment of wheels:

[0051] At temperature T3, the secondary additive wheel is subjected to homogenization heat treatment for 8 hours to 24 hours, and finally cooled to room temperature in air to obtain a homogenized secondary additive wheel;

[0052] 6. Overall forging of wheels:

[0053] The homogenized secondary additive wheel and the forging die are lubricated, and then the homogenized secondary additive wheel is heated to the aluminum alloy forging temperature T4 and kept warm, and the forging die is preheated to the temperature T5, and then the homogenized secondary additive wheel is placed in the forging die and positioned, and the homogenized secondary additive wheel is forged as a whole at a pressing speed of 2.5 mm / s to 12.8 mm / s, and finally quickly cooled to room temperature, and the flash is removed to obtain the wheel final forging;

[0054] 7. Direct aging strengthening treatment of wheels:

[0055] The wheel final forging is subjected to artificial aging strengthening treatment and then cooled to room temperature in air, thereby completing the additive forging composite forming method of the aluminum alloy lightweight wheel-shaped component with overall loading and local deformation.

[0056] The beneficial effects of this embodiment are:

[0057] The present embodiment provides an additive forging composite forming method for an aluminum alloy lightweight wheel-shaped component with overall loading and local deformation, comprising preparing a wheel additive blank by an arc additive manufacturing method, pre-forging the wheel additive blank in a mold to form a spoke with a total required reduction of 40% to 60%, removing flash and surface finishing, then performing secondary additive work at the rim of the pre-forged component to supplement the material, performing overall homogenization treatment on the secondary additively produced wheel, and then performing overall forging in the same mold to obtain a wheel final forging that is fully filled, free of defects such as cracks and pores, and has a qualified shape and size, and finally performing artificial aging strengthening treatment to obtain a wheel part that meets the requirements in terms of final mechanical properties and shape and size.

[0058] This embodiment uses an arc wire feeding additive manufacturing method to prepare a billet with a certain complex structure shape, replacing the traditional multiple billet making process, shortening the manufacturing process and saving mold costs and forging billet costs, while improving material utilization. After the additive billet is pre-forged, secondary additive filling is performed on the wheel rim part, and then the overall forging is performed, which ensures that the die cavity of the high wheel rim part of the forging is completely filled, and solves the problem of insufficient filling of the high-rib deep cavity part with a large aspect ratio in the traditional one-step forging forming; at the same time, the secondary additive filling method improves the forging flexibility, and the same set of forging dies are used for the two forgings of pre-forging and overall forging, which greatly saves the mold manufacturing cost.

[0059] This embodiment is formed by two forgings, pre-forging and integral forging, wherein the metal volume of the spoke part of the additive blank is larger than the spoke part of the final forging, and its excess metal flows into the flash during the two forging processes, thereby ensuring sufficient deformation of the spoke part and preventing the thinner spoke part from becoming unstable during the forging process; the rim part of the additive blank undergoes a certain amount of deformation during the pre-forging process, and the integral forging after the secondary additive process further increases the overall deformation of the rim, thereby ensuring sufficient deformation of the rim part; the sufficient deformation of the arc additive blank enables the defects of additive pores, cracks, and unfused materials to be fully forged, thereby reducing the brittleness of the additive component and improving fatigue performance, while significantly improving the additive layered structure and reducing the anisotropy of the mechanical properties of the additive component, thereby solving the problems of large residual stress, sensitive pore defects, and poor structure and mechanical properties of directly additive wheel components.

[0060] This embodiment improves the uniformity of the microstructure and performance of the additive component by performing an overall homogenization heat treatment after the secondary additive process, while narrowing the microstructure and performance gap between the pre-forged part and the secondary additive part, improving the deformation coordination of the two parts during the subsequent overall forging process, and effectively preventing the difficulty of forging filling and the uneven microstructure and performance of the final forging caused by uneven deformation. In addition, the additive-forging interface between the pre-forged part and the secondary additive part generates sufficient flow during the subsequent overall forging process, which can significantly eliminate defects such as poor fusion at the interface, improve the interface structure, and increase the interface bonding strength.

[0061] Specific embodiment 2: This embodiment differs from specific embodiment 1 in that the raw materials used for arc wire additive manufacturing described in step 1 and step 4 are the same material, 2xxx series aluminum alloy or 7xxx series aluminum alloy. The rest is the same as specific embodiment 1.

[0062] Specific implementation method three: This implementation method is different from specific implementation methods one or two in that: the wheel spokes in the wheel material-enhancing blank described in step one are partially hollowed structures; the size of a single hollow hole of the wheel spokes in the wheel material-enhancing blank described in step one is 1.1 to 1.4 times the size of a single hollow hole of the wheel spokes in the wheel final forging described in step six, and the sizes are length and width; the thickness of the wheel spokes in the wheel material-enhancing blank described in step one is 2 to 2.5 times the thickness of the wheel spokes in the wheel final forging described in step six; the height of the wheel rim in the wheel material-enhancing blank described in step one is 50% to 70% of the height of the wheel rim in the wheel final forging described in step six; the width of the wheel rim in the wheel material-enhancing blank described in step one is 1.6 to 2 times the width of the wheel rim in the wheel final forging described in step six. Others are the same as specific implementation methods one or two.

[0063] Specific embodiment 4: This embodiment is different from one of specific embodiments 1 to 3 in that: the reduction amount of the spoke pre-forging process described in step 2 is 40% to 60% of the reduction amount required for the forging die to be completely closed; the spoke thickness in the wheel pre-forging described in step 2 is 1 to 1.3 times the spoke thickness in the wheel final forging described in step 6. It is the same as specific embodiments 1 to 3.

[0064] Specific implementation method 5: This implementation method is different from any one of specific implementation methods 1 to 4 in that: the height of the rim in the secondary material-added wheel described in step 4 is 75% to 90% of the height of the rim in the wheel final forging described in step 6; the width of the rim in the secondary material-added wheel described in step 4 is 1.1 to 1.6 times the width of the rim in the wheel final forging described in step 6, and the inner and outer surfaces of the rim in the secondary material-added wheel are parallel to the rim axis. The rest is the same as specific implementation methods 1 to 4.

[0065] Specific embodiment 6: This embodiment is different from specific embodiments 1 to 5 in that the temperature T3 described in step 5 is the solution heat treatment temperature of the aluminum alloy. The rest is the same as specific embodiments 1 to 5.

[0066] The solution heat treatment temperature of the aluminum alloy described in this specific embodiment can be based on the standard solution heat treatment temperature of different aluminum alloys specified in the non-ferrous metal industry standard YS / T591-2017 Deformed Aluminum and Aluminum Alloy Heat Treatment, that is, the homogenization heat treatment temperature used in this specific embodiment is the same as the temperature in this standard.

[0067] Specific embodiment 7: This embodiment differs from specific embodiments 1 to 6 in that: in step 6, the method of spraying or water quenching is used to quickly cool to room temperature. The rest is the same as specific embodiments 1 to 6.

[0068] Specific embodiment 8: This embodiment differs from specific embodiments 1 to 7 in that: in step 2, T1=T2, and T1 is the aluminum alloy forging temperature; in step 6, T4=T5, and T4 is 85% to 95% of T1. Other aspects are the same as specific embodiments 1 to 7.

[0069] The aluminum alloy forging temperature described in this specific embodiment may be 70% to 80% of the aluminum alloy melting point.

[0070] Specific embodiment 9: This embodiment is different from specific embodiments 1 to 8 in that the forging die described in step 6 is the same as the forging die described in step 2. The rest is the same as specific embodiments 1 to 8.

[0071] Specific embodiment 10: This embodiment differs from specific embodiments 1 to 9 in that the pressing amount during the integral forging process described in step 6 is the pressing amount required for the die to be completely closed. The rest is the same as specific embodiments 1 to 9.

[0072] The following examples are used to verify the beneficial effects of the present invention:

[0073] Embodiment 1:

[0074] An additive forging composite forming method for an aluminum alloy lightweight wheel-shaped component with overall loading and local deformation is carried out in the following steps:

[0075] 1. Additive forming of main blank:

[0076] Using 2219 aluminum alloy welding wire as raw material, the wheel body is formed by using the cold metal transition arc wire feeding additive manufacturing method, and then the surface of the wheel body is polished and smoothed to obtain the wheel additive blank;

[0077] The wheel augmented material blank is formed by connecting a rim and a spoke, and the transition fillet between the spoke and the rim is R5; 7 hollow holes are evenly arranged along the circumference of the spoke in the wheel augmented material blank, and a circular hole with a diameter of 120 mm is arranged in the middle; the length of a single hollow hole is 120 mm, the width is 74 mm, and the spoke thickness is 20 mm; the outer diameter of the rim in the wheel augmented material blank is 560 mm, the rim width is 50 mm, and the rim height is 130 mm;

[0078] 2. Spoke pre-forging and forming:

[0079] Graphite lubricant is sprayed on the surface of the wheel additive blank and the forging die, and then the wheel additive blank is heated to 450°C and kept at 450°C for 90 minutes. At the same time, the forging die is preheated to 450°C, and then the wheel additive blank is placed in the forging die and positioned. At a pressing speed of 2.5 mm / s, the spokes of the wheel additive blank are pre-forged and formed. Finally, it is cooled to room temperature in air, and the flash is removed to obtain a wheel pre-forged part.

[0080] The forging die is an open die forging die;

[0081] The amount of reduction during the spoke pre-forging process is 50% of the amount of reduction required for the forging die to be completely closed;

[0082] The transition fillet between the spoke and the rim in the wheel preforging is R20; 7 hollow holes are evenly arranged along the circumference of the spoke in the wheel preforging, and a circular hole with a diameter of 110 mm is arranged in the middle; the length of a single hollow hole is 115 mm and the width is 64 mm, and a triangular indentation with a side length of 40 mm is arranged between two adjacent hollow holes, and the spoke thickness is 15 mm; the outer diameter of the rim in the wheel preforging is 563 mm, the rim width is 30 mm, and the rim height is 150 mm;

[0083] 3. Machining and finishing of pre-forgings:

[0084] The triangular indentation of the wheel preforging is removed by milling and angle grinder grinding, and then the upper and lower end faces of the wheel rim of the wheel preforging are processed flat, and the oxide layers on the inner and outer surfaces of the wheel rim are ground off to obtain a trimmed preforging;

[0085] The transition fillet between the spoke and the rim in the trimmed pre-forged part is R20; 7 hollow holes are evenly arranged along the circumference of the spoke in the trimmed pre-forged part, and a circular hole with a diameter of 110 mm is set in the middle; the length of a single hollow hole is 115 mm and the width is 64 mm, and a triangular hole with a side length of 40 mm is set between two adjacent hollow holes, and the spoke thickness is 15 mm; the outer diameter of the rim in the wheel pre-forged part is 563 mm, the rim width is 30 mm, and the rim height is 130 mm;

[0086] 4. Secondary material addition of wheel rims:

[0087] Using 2219 aluminum alloy welding wire as raw material, the upper and lower end faces of the rim and the inner and outer surfaces of the rim in the trimmed pre-forged part are subjected to secondary additive forming by using the cold metal transition arc wire feeding additive manufacturing method, and then polished to obtain a secondary additive wheel;

[0088] The transition fillet between the spoke and the rim in the secondary additive wheel is R20; 7 hollow holes are evenly arranged along the circumference of the spoke in the secondary additive wheel, and a circular hole with a diameter of 110 mm is set in the middle; the length of a single hollow hole is 115 mm and the width is 64 mm, and a triangular hole with a side length of 40 mm is set between two adjacent hollow holes, and the spoke thickness is 15 mm; the outer diameter of the rim in the secondary additive wheel is 563 mm, the rim width is 35 mm, and the rim height is 190 mm; and the inner and outer surfaces of the rim in the secondary additive wheel are parallel to the rim axis;

[0089] 5. Overall uniform heat treatment of wheels:

[0090] The secondary additive wheel was subjected to homogenization heat treatment at a temperature of 510°C for 8 hours, and finally cooled to room temperature in air to obtain a homogenized secondary additive wheel;

[0091] 6. Overall forging of wheels:

[0092] Graphite lubricant is sprayed on the surface of the homogenized secondary additive wheel and the forging die, and then the homogenized secondary additive wheel is heated to 420°C and kept at 420°C for 90 minutes. At the same time, the forging die is preheated to 420°C, and then the homogenized secondary additive wheel is placed in the forging die and positioned. At a pressing speed of 2.5 mm / s, the homogenized secondary additive wheel is forged as a whole, and finally quickly cooled to room temperature by water quenching, and the flash is removed to obtain the final wheel forging;

[0093] The forging die described in step 6 is the same as the forging die described in step 2; the pressing amount during the integral forging process is the pressing amount required for the die to be completely closed;

[0094] The transition fillet between the spoke and the rim in the wheel final forging is R20; 7 hollow holes are evenly arranged along the circumference of the spoke in the wheel final forging, and a circular hole with a diameter of 110 mm is set in the middle; the length of a single hollow hole is 110 mm and the width is 54 mm, and a triangular hole with a side length of 40 mm is set between two adjacent hollow holes, and the spoke thickness is 10 mm; the outer diameter of the rim in the wheel final forging is 563 mm, the rim width is 22 mm, and the rim height is 220 mm;

[0095] 7. Direct aging strengthening treatment of wheels:

[0096] The wheel final forging was subjected to artificial aging strengthening treatment at a temperature of 165°C for 16 hours, and then cooled to room temperature in air to obtain the aged final forging.

[0097] In step 4 of this embodiment, the maximum outer diameter of the wheel rim does not change. Since the outer ring has an inclination, the outer inclination is filled after the outer side is increased, so the outer ring becomes a straight wall.

[0098] Comparative experiment 1:

[0099] A 2219 aluminum alloy forging billet is used to obtain a wheel forging billet by machining. The forging billet and the die are heated to 450°C and kept warm. Then, the forging billet is placed in the die and forged at a pressing speed of 2.5 mm / s. After forging, the billet is cooled to room temperature in air, and then subjected to a solution treatment at 535°C / 2h and an aging treatment at 120°C / 24h to obtain a wheel forging formed in one step.

[0100] Comparative experiment 2: Using 2219 aluminum alloy welding wire as raw material, the wheel final forging described in step six of Example 1 is directly formed in one step by using the cold metal transition arc wire feeding additive manufacturing method. Then, at a temperature of 165°C, the wheel final forging is subjected to artificial aging strengthening treatment for 16 hours, and then cooled to room temperature in air to obtain the aged final forging.

[0101] Figure 1 For comparison purposes, a schematic diagram of the one-time forging forming of a wheel-shaped component using the traditional process is provided. A is before forging, A is the upper die, B is the wheel forging blank, C is the lower die, b is after forging, and D is the unfilled part. As can be seen from the figure, due to the large height-to-thickness ratio of the final forging (the height-to-thickness ratio is 5:1), it is difficult to completely fill the edge of the forged wheel rim in one time.

[0102] Figure 2 This is a schematic diagram of the structure of the wheel additive blank prepared in step 1 of Example 1;

[0103] Figure 3 Schematic diagram of the die cavity of the forging die used in step 2 and step 6 of Example 1, a is the upper die, b is the lower die, and c is a schematic diagram of the longitudinal section of the die cavity in the closed state of the die;

[0104] Figure 4 : This is the finite element simulation result of the spoke pre-forging forming process in step 2 of Example 1, a is a schematic diagram of the wheel pre-forging without removing the flash, and b is a local strain cloud diagram of the wheel pre-forging. It can be seen from the figure that the strain of the spoke part after pre-forging is above 0.5, the rim part also produces a certain amount of deformation, and there is no folding defect at the transition radius between the spoke and the rim.

[0105] Figure 5 This is a schematic diagram of the trimmed pre-forged part prepared in step 3 of Example 1;

[0106] Figure 6 Schematic diagram of a secondary material addition wheel prepared in step 4 of Example 1, where A is the secondary material addition position on the upper and lower end surfaces of the wheel rim;

[0107] Figure 7 It is the finite element simulation result of the integral forging process of the wheel in step six of Example 1, a is the final wheel forging without removing the flash, and b is the local strain cloud diagram of the final wheel forging; it can be seen from the figure that the strain of the final forging in the whole domain reaches more than 0.5, and the strain of key load-bearing parts such as the transition between the spoke and rim and the outer edge of the rim can reach more than 1, and the overall deformation is sufficient to ensure that the defects of the additive are completely forged and the additive organization is fully improved; and the difficult-to-fill parts on the edge of the rim are completely filled, the final forging is fully formed, without defects such as cracks and pores, and the shape and size are qualified.

[0108] Figure 8 This is a schematic diagram of the structure of the wheel final forging prepared in step six of Example 1; as can be seen from the figure, the forging formed by this method has a high degree of conformality, a small machining allowance, a high material utilization rate, cost savings, and the shape and size meet the requirements.

[0109] Fig. 9 The figure is a comparison diagram of the final forging microstructures after aging prepared in Example 1 and Comparative Experiment 2, where a is Comparative Experiment 2 and b is Example 1. It can be seen from the figure that the microstructure of the direct additive forming in Comparative Experiment 2 has uneven grain size and an obvious layered structure. The microstructure formed by the method of Example 1 has fine and uniform grains and no layered structure, which proves that this method can significantly improve the additive structure.

[0110] Fig.10 The defects of the final forgings after aging prepared in Example 1 and Comparative Experiment 2 are compared, a is Comparative Experiment 2, and b is Example 1; in Comparative Experiment 2, direct additive forming is used, and a large number of pores (A) and unfused (B) defects exist inside the alloy; in Example 1, the method for forming is used, and there are no defects such as pores inside, and the structure is dense, which proves that this method can effectively eliminate additive defects.

[0111] Samples were taken from the spokes of the final forging after aging and tensile tested at a rate of 0.001s -1 Mechanical properties test was carried out under the conditions of Fig.11 The room temperature mechanical properties of the final forgings after aging prepared in Example 1 and Comparative Experiment 2 are compared, A is Comparative Experiment 2, and B is Example 1; as can be seen from the figure, the room temperature tensile curve of the direct additively formed component in Comparative Experiment 2 has a tensile strength of only 265 MPa and a low elongation; the room temperature tensile curve of the component formed by the method of Example 1 has a tensile strength of 385 MPa, an increase of 31.1%, and the elongation is also significantly improved, proving that its strength and toughness are higher than those of direct additively formed components.

Claims

1. An additive forging composite forming method for an aluminum alloy lightweight wheel-shaped component with overall loading and local deformation, characterized in that It is carried out in the following steps:

1. Additive forming of main blank: The wheel body is formed by using an arc wire feeding additive manufacturing method, and then the surface of the wheel body is polished and smoothed to obtain a wheel additive blank; The wheel additive blank is formed by connecting a wheel rim and a wheel spoke; 2. Spoke pre-forging and forming: The wheel additive blank and the forging die are lubricated, and then the wheel additive blank is heated to the aluminum alloy forging temperature T1 and kept warm, and the forging die is preheated to the temperature T2, and then the wheel additive blank is placed in the forging die and positioned, and the spokes of the wheel additive blank are pre-forged at a pressing speed of 2.5 mm / s to 12.8 mm / s, and finally cooled to room temperature in air, and the flash is removed to obtain a wheel pre-forged part; 3. Machining and finishing of pre-forgings: The upper and lower end surfaces of the wheel rim of the wheel preforging are processed to be flat, and the oxide layers on the inner and outer surfaces of the wheel rim are polished off to obtain a trimmed preforging; 4. Secondary material addition of wheel rims: Using an arc wire feeding additive manufacturing method, secondary additive forming is performed on the upper and lower end faces of the rim and the inner and outer surfaces of the rim in the trimmed pre-forged part, and then polished to obtain a secondary additive wheel; 5. Overall uniform heat treatment of wheels: At temperature T3, the secondary additive wheel is subjected to homogenization heat treatment for 8 hours to 24 hours, and finally cooled to room temperature in air to obtain a homogenized secondary additive wheel; 6. Overall forging of wheels: The homogenized secondary additive wheel and the forging die are lubricated, and then the homogenized secondary additive wheel is heated to the aluminum alloy forging temperature T4 and kept warm, and the forging die is preheated to the temperature T5, and then the homogenized secondary additive wheel is placed in the forging die and positioned, and the homogenized secondary additive wheel is forged as a whole at a pressing speed of 2.5 mm / s to 12.8 mm / s, and finally quickly cooled to room temperature, and the flash is removed to obtain the wheel final forging; 7. Direct aging strengthening treatment of wheels: The wheel final forging is subjected to artificial aging strengthening treatment and then cooled to room temperature in air, thereby completing the additive forging composite forming method of the aluminum alloy lightweight wheel-shaped component with overall loading and local deformation.

2. The additive forging composite forming method of an aluminum alloy lightweight wheel-shaped component with overall loading and local deformation according to claim 1 is characterized in that The raw materials used in the arc wire additive manufacturing described in step 1 and step 4 are made of the same material, which is 2xxx series aluminum alloy or 7xxx series aluminum alloy.

3. The additive forging composite forming method of an aluminum alloy lightweight wheel-shaped component with overall loading and local deformation according to claim 1 is characterized in that The spokes in the wheel augmented material blank described in step one are partially hollowed out structures; the size of a single hollow hole of the spokes in the wheel augmented material blank described in step one is 1.1 to 1.4 times the size of a single hollow hole of the spokes in the wheel final forging described in step six, and the sizes are length and width; the thickness of the spokes in the wheel augmented material blank described in step one is 2 to 2.5 times the thickness of the spokes in the wheel final forging described in step six; the height of the rim in the wheel augmented material blank described in step one is 50% to 70% of the height of the rim in the wheel final forging described in step six; the width of the rim in the wheel augmented material blank described in step one is 1.6 to 2 times the width of the rim in the wheel final forging described in step six.

4. The additive forging composite forming method of an aluminum alloy lightweight wheel-shaped component with overall loading and local deformation according to claim 1 is characterized in that The amount of reduction in the pre-forging process of the spoke described in step 2 is 40% to 60% of the amount of reduction required for the forging die to be completely closed; the thickness of the spoke in the wheel pre-forging described in step 2 is 1 to 1.3 times the thickness of the spoke in the wheel final forging described in step 6.

5. The additive forging composite forming method of an aluminum alloy lightweight wheel-shaped component with overall loading and local deformation according to claim 1 is characterized in that The rim height of the secondary additively manufactured wheel in step 4 is 75% to 90% of the rim height of the wheel final forging in step 6; the rim width of the secondary additively manufactured wheel in step 4 is 1.1 to 1.6 times the rim width of the wheel final forging in step 6, and the inner and outer surfaces of the rim in the secondary additively manufactured wheel are parallel to the rim axis.

6. The additive forging composite forming method of an aluminum alloy lightweight wheel-shaped component with overall loading and local deformation according to claim 1 is characterized in that The temperature T3 described in step 5 is the solution heat treatment temperature of the aluminum alloy.

7. The additive forging composite forming method of an aluminum alloy lightweight wheel-shaped component with overall loading and local deformation according to claim 1 is characterized in that In step six, the material is rapidly cooled to room temperature by spraying or water quenching.

8. The additive forging composite forming method of an aluminum alloy lightweight wheel-shaped component with overall loading and local deformation according to claim 1 is characterized in that In step 2, T1=T2, and T1 is the forging temperature of the aluminum alloy; in step 6, T4=T5, and T4 is 85% to 95% of T1.

9. The additive forging composite forming method of an aluminum alloy lightweight wheel-shaped component with overall loading and local deformation according to claim 1, characterized in that The forging die described in step six is ​​the same as the forging die described in step two.

10. The additive forging composite forming method of an aluminum alloy lightweight wheel-shaped component with overall loading and local deformation according to claim 1, characterized in that The amount of reduction during the integral forging process described in step six is ​​the amount of reduction required for the die to be completely closed.

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