Integrated manned lunar rover wheel hub made of dissimilar materials and forging-material adding-re-forging integral forming method of integrated manned lunar rover wheel hub made of dissimilar materials

Abstract

The invention discloses a dissimilar material integrated manned lunar rover wheel hub and a forging-material adding-re-forging integral forming method thereof, and relates to manned lunar rover wheel hubs and forming methods thereof. The invention aims to solve the problem that the wheel-shaped component made of the dissimilar aluminum alloy material is difficult to integrally form. An integrated manned lunar rover wheel hub made of dissimilar materials is formed by connecting a rim and a spoke, the rim is composed of a rim body, an outer ring assembling ring and strip-shaped reinforcing ribs, and the spoke is composed of a plurality of Y-shaped sheet-shaped thin plates, an axle assembling flange and a transition area. The method comprises the steps of 1, blank making; 2, forging and forming a rim and a transition area; 3, finishing an additive interface; 4, adding materials; 5, homogenizing heat treatment; sixthly, integral forging forming is conducted; 7, aging strengthening treatment; and 8, machining and forming the wheel part. The method is used for the dissimilar material integrated manned lunar rover wheel hub and forging-material adding-re-forging integral forming of the dissimilar material integrated manned lunar rover wheel hub.

Description

Technical Field

[0001] The invention relates to a wheel hub of a manned lunar rover and a forming method thereof. Background Art

[0002] As my country's lunar exploration project enters a new stage, the manned lunar landing project has fully carried out relevant research work. As one of the most important equipment for the manned lunar landing project, the manned lunar rover is quite different from the traditional lunar surface travel equipment in terms of material selection, structural design, performance requirements, etc. Among them, the requirements for high performance, long life and lightweight of each load-bearing component are further improved, so higher requirements are also put forward for the design and manufacture of components.

[0003] Space wheel-shaped components, such as the wheels of manned lunar rovers, have the following characteristics: their spokes and rims are thin-walled structures, and have a large number of topological structures designed for lightweight requirements. This structure can reduce the weight of the components to the greatest extent while meeting the support strength, so as to reduce the overall fuel consumption and maximize the load-bearing capacity. In addition, during the service of space wheel-shaped components, the spokes play a major supporting role, so they need to have higher strength, while the rims are subject to more vibration and friction, so they need to have higher toughness and fatigue resistance. Different positions of the same component have different performance requirements, so it is necessary to use heterogeneous materials to form the overall component.

[0004] Aerospace high-strength aluminum alloys mainly include 2xxx series and 7xxx series aluminum alloys. Among them, 2xxx series aluminum alloys have good plasticity and toughness, and the room temperature elongation can reach more than 12%, while 7xxx series aluminum alloys have higher strength, and the room temperature strength can reach more than 550MPa. In addition, the density of aluminum alloy is only 2.8g / cm 3 , which can simultaneously meet the needs of high strength and lightweight for aerospace components. Among them, the high toughness of 2xxx series aluminum alloys and the high strength of 7xxx series aluminum alloys can perfectly match the performance requirements of aerospace wheel-shaped components, and are very suitable for the preparation of aerospace wheel-shaped components.

[0005] However, the current forming methods of dissimilar material components all have defects. For example, if the method of forming and then welding is used, the welded joints are weak and prone to fatigue damage; if the two material parts are connected by riveting, the rivets will greatly increase the weight of the component; if the component is formed by additive manufacturing, the defects of additive manufacturing are difficult to eliminate, which will significantly reduce the mechanical properties of the component. In summary, there is currently a lack of a method that can achieve the overall forming of dissimilar materials while ensuring excellent component structure and performance. Summary of the invention

[0006] The present invention aims to solve the problem that wheel-shaped components made of heterogeneous aluminum alloy materials are difficult to be integrally formed, and further provides a heterogeneous material one-piece manned lunar rover wheel hub and a forging-additive-reforging integral forming method thereof.

[0007] A wheel hub of a manned lunar rover with an integrated structure of heterogeneous materials, which is formed by connecting a wheel rim and a wheel spoke; the wheel rim is composed of a wheel rim body, an outer ring assembly ring and strip reinforcement ribs; the wheel rim body is a cylindrical structure; outer ring assembly rings are provided at both ends of the wheel rim body; a plurality of strip reinforcement ribs are provided along the axial direction on the outer surface of the wheel rim body, and the plurality of strip reinforcement ribs are distributed in a ring shape with equal spacing, and both ends of a single strip reinforcement rib are connected to the outer ring assembly ring; the wheel spoke is composed of a plurality of Y-shaped sheet-like thin plates, an axle assembly flange and a transition area; the plurality of Y-shaped sheet-like thin plates are distributed in a ring shape with equal spacing, and one end is connected to the axle assembly flange, and the other end is connected to the inner edge of the transition area, and the outer edge of the transition area is connected to the inner surface of the wheel rim body; the plurality of Y-shaped sheet-like thin plates and the transition area constitute a spoke plate;

[0008] The height H1 of the wheel rim body is 150 mm to 250 mm, the outer diameter D1 is 500 mm to 600 mm, and the wall thickness t1 is 1 mm to 3 mm; the thickness of the spoke is t2, t2=(2 to 4) t1; the angle of the fork of the Y-shaped sheet is 30° to 60°, and the width of the branch is 15 mm to 50 mm; the inner diameter of the transition area is D2, D2=(0.7 to 0.85) D1;

[0009] The material of the wheel rim and the transition area is 2xxx series aluminum alloy material; the material of the multiple Y-shaped sheet plates and the axle assembly flange is 7xxx series aluminum alloy material.

[0010] A forging-adding-reforging integral forming method of a wheel hub of a manned lunar rover with one piece of heterogeneous materials is carried out in the following steps:

[0011] 1. Blank making:

[0012] Processing a forging blank to obtain a forging blank;

[0013] The forging blank is composed of a wheel rim main body blank and a transition area blank, and the outer edge of the transition area blank is connected to the inner surface of the wheel rim main body blank;

[0014] 2. Forging of rims and transition areas:

[0015] The forging blank and the forging die are lubricated, and then the forging 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 forging blank is placed in the forging die and positioned, and the forging blank is forged at a pressing speed of 2.5 mm / s to 12.8 mm / s, and finally cooled to room temperature in air to obtain a forging;

[0016] The forgings are composed of a wheel rim main body forging and a transition area forging;

[0017] 3. Additive interface finishing:

[0018] An annular groove is machined on the forging in the transition area;

[0019] 4. Additives:

[0020] Using the arc wire feeding additive manufacturing method, multiple Y-shaped sheet blanks and internal ring blanks are formed at the annular groove of the transition area forging, and then polished and trimmed to obtain the wheel composite material;

[0021] 5. Homogenization heat treatment:

[0022] Performing a homogenized heat treatment on the wheel composite material, and finally cooling it to room temperature in air to obtain a homogenized wheel composite material;

[0023] 6. Overall forging forming:

[0024] The homogenized wheel composite material and the forging die are lubricated, and then the homogenized wheel composite material is heated to the aluminum alloy forging temperature T3 and kept warm, and the forging die is preheated to the temperature T4, and then the homogenized wheel composite material is placed in the forging die and positioned, and the homogenized wheel composite material 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;

[0025] 7. Time-intensive treatment:

[0026] The wheel final forging is subjected to artificial aging strengthening treatment, and then cooled to room temperature in air to obtain the final forging after aging;

[0027] 8. Machining of wheel parts:

[0028] The wheel final forging after aging treatment is machined to obtain a heterogeneous material one-piece manned lunar rover wheel hub.

[0029] The beneficial effects of the present invention are:

[0030] The present invention provides a heterogeneous material integrated manned lunar rover wheel hub and a forging-additive-reforging integral forming method thereof, comprising forging and forming a 2xxx series aluminum alloy wheel rim main body blank and a transition area blank, adding a 7xxx series aluminum alloy Y-shaped sheet blank and an inner ring blank at the interface after trimming the additive interface, subjecting the obtained heterogeneous material composite blank to an overall homogenization heat treatment, and then forging and forming the entirety thereof, and obtaining a final heterogeneous material composite part through subsequent direct aging and machining.

[0031] The present invention obtains a well-connected integral billet of dissimilar materials by adding dissimilar materials to a forging blank, and realizes integral forming of the dissimilar materials through integral forging. The prepared component has good integrity and uniform organizational transition, and there will be no organizational mutation that causes excessive performance differences in different regions. At the same time, the dissimilar materials are self-connected to avoid additional connection structures that cause weight gain in the overall component, thereby meeting the lightweight requirements of the component.

[0032] The present invention reduces the difference in deformation resistance of two different materials during the forging process by performing overall homogenization heat treatment on the dissimilar material blanks, improves the deformation coordination and organizational uniformity of the dissimilar material forging, effectively prevents defects such as cracking of the coarse additive organization during the forging process, and improves the quality of the forgings.

[0033] The present invention performs integral forging forming on the homogenized dissimilar material blank, applies effective metal flow to the inside of the additive blank and the interface of the dissimilar materials, improves the additive structure through forging deformation, forges defects such as pores and cracks of the additive, eliminates the additive residual stress, improves the strength of the additive part and eliminates the brittleness of the additive; improves the interface structure of the dissimilar materials through forging deformation, utilizes the interface metal flow to disrupt the interface boundary line, forms an interface structure transition zone, promotes element diffusion on both sides of the interface, improves the uniformity of the structure on both sides of the interface and prevents the structure and mechanical properties from suddenly changing at the interface, and at the same time forges defects such as poor bonding at the interface, improves the interface bonding strength, and prevents the interface from becoming a performance weak zone of the component.

[0034] The present invention can realize the integral forming of aluminum alloy components of different materials, shorten the manufacturing cycle, further reduce the weight of components while ensuring that the organizational performance of components meets the standards, liberate the structural and material design ideas of aerospace lightweight components, effectively improve the material-performance matching of aerospace lightweight components, and provide a new direction for the design and preparation of lightweight components for a new generation of spacecraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A three-dimensional diagram of the wheel hub of the manned lunar rover made of one piece of heterogeneous materials according to the present invention;

[0036] Figure 2 It is a cross-sectional view of the wheel hub of the manned lunar rover made of one piece of heterogeneous materials according to the present invention;

[0037] Figure 3 This is a flow chart of the forging-addition-reforging integral forming of a wheel hub of a manned lunar rover made of one piece of heterogeneous materials in Example 1;

[0038] Figure 4 It is a schematic diagram of the longitudinal section of the die bore of the forging die described in step 2 and step 6 of embodiment 1;

[0039] Figure 5The finite element simulation results of the forging forming process in step 2 of Example 1, a is the strain nephogram before forging, and b is the strain nephogram after forging;

[0040] Figure 6 This is a schematic diagram of processing an annular groove in step 3 of embodiment 1, where A is the annular groove;

[0041] Figure 7 Schematic diagram of the interface position of the additive material in step 4 of Example 1, a is a schematic diagram of preparing a wheel composite material, in which A is the interface position of the additive material, and b is an enlarged view of position A in a;

[0042] Figure 8 The finite element simulation results of the integral forging forming process in step 6 of Example 1, a is the strain cloud diagram before forging, and b is the strain cloud diagram after forging;

[0043] Fig. 9 This is a finite element analysis diagram of the load condition of the heterogeneous material integrated manned lunar rover wheel hub prepared in Example 1, where a is the deformation under load and b is the stress condition of the wheel under load. DETAILED DESCRIPTION

[0044] Specific implementation method 1, combined with Figure 1 and Figure 2 Description: This embodiment is a wheel hub of a manned lunar rover with an integrated structure of heterogeneous materials, which is connected by a wheel rim and a spoke; the wheel rim is composed of a wheel rim body 11, an outer ring assembly ring 12 and strip reinforcement ribs 13; the wheel rim body 11 is a cylindrical structure; outer ring assembly rings 12 are provided at both ends of the wheel rim body 11; a plurality of strip reinforcement ribs 13 are axially provided on the outer surface of the wheel rim body 11, and the plurality of strip reinforcement ribs 13 are distributed in an annular shape with equal spacing, and both ends of a single strip reinforcement rib 13 are connected to the outer ring assembly ring 12; the spoke is composed of a plurality of Y-shaped sheet-like thin plates 21, an axle assembly flange 22 and a transition area 23; the plurality of Y-shaped sheet-like thin plates 21 are distributed in an annular shape with equal spacing, and one end is connected to the axle assembly flange 22, and the other end is connected to the inner edge of the transition area 23, and the outer edge of the transition area 23 is connected to the inner surface of the wheel rim body 11; the plurality of Y-shaped sheet-like thin plates and the transition area 23 constitute a spoke plate;

[0045] The height H1 of the wheel rim body 11 is 150 mm to 250 mm, the outer diameter D1 is 500 mm to 600 mm, and the wall thickness t1 is 1 mm to 3 mm; the thickness of the spoke is t2, t2=(2 to 4) t1; the angle of the fork of the Y-shaped sheet 21 is 30° to 60°, and the width of the branch is 15 mm to 50 mm; the inner diameter of the transition area 23 is D2, D2=(0.7 to 0.85) D1;

[0046] The material of the wheel rim and the transition area 23 is 2xxx series aluminum alloy material; the material of the multiple Y-shaped sheet plates 21 and the axle assembly flange 22 is 7xxx series aluminum alloy material.

[0047] Principle: The service environment of the wheel-shaped components of manned spacecraft is the ground in deep space environments such as the moon or Mars. As a moving mechanism, it needs to carry the entire deep space exploration equipment and manned cargo. It has the characteristics of large load, long required life, complex service environment, and great influence by rugged surface conditions and sand and stone particles. At the same time, there is a very high demand for lightweight components.

[0048] In terms of material selection, during the service life of the component, the wheel rim is subject to more vibration and requires high toughness, while the spoke supports the entire spacecraft and requires high strength. Considering the overall load-bearing and lightweight requirements of the component, the wheel is made of aluminum alloy, of which the wheel rim and transition area are made of 2xxx series aluminum alloy with higher toughness, while the Y-shaped sheet and axle assembly flange are made of 7xxx series aluminum alloy with higher strength. The two materials are not connected by mechanical means such as riveting, but are formed to achieve metallurgical bonding between the two, thereby ensuring the strength of the joint and meeting the lightweight requirements of the component.

[0049] In terms of structural design, the outer assembly ring area of ​​the rim is subject to outward tension, so reinforcing ribs are arranged on the outer ring to reduce deformation of the outer ring, increase the stiffness of the outer ring, and disperse stress at the same time; the spokes are the main load-bearing structure, and considering the overall lightweight requirements of the components, the spokes are designed as a Y-shaped distributed support structure to better disperse stress; at the same time, in order to adapt to the drive and steering mechanisms, thin-walled spokes and barrel-shaped rim structures are adopted as a whole to reserve space for the drive and steering mechanisms, and the axle assembly flange area on the spokes is not in the center, but there is a certain amount of offset.

[0050] The beneficial effects of this embodiment are:

[0051] The present embodiment provides a dissimilar material integrated manned lunar rover wheel hub and a forging-additive-reforging integral forming method thereof, including forging and forming of a 2xxx series aluminum alloy rim main body blank and a transition area blank, adding a 7xxx series aluminum alloy Y-shaped sheet blank and an inner ring blank at the interface after trimming the additive interface, subjecting the obtained dissimilar material composite blank to an overall homogenization heat treatment and then forging it as a whole, and obtaining a final dissimilar material composite part through subsequent direct aging and machining.

[0052] This embodiment adds dissimilar materials to the forging blank to obtain a well-connected overall blank of dissimilar materials, and realizes the overall forming of the dissimilar materials through overall forging. The prepared component has good integrity and uniform organizational transition, and there will be no organizational mutation that causes excessive performance differences in different regions. At the same time, the self-connection of dissimilar materials avoids the increase in weight of the overall component due to additional connection structures, which can meet the lightweight requirements of the component.

[0053] This embodiment reduces the difference in deformation resistance of two different materials during the forging process by performing overall homogenization heat treatment on the dissimilar material billets, improves the deformation coordination and organizational uniformity of the dissimilar material forging, and effectively prevents defects such as cracking of the coarse additive structure during the forging process, thereby improving the quality of the forgings.

[0054] This embodiment applies effective metal flow to the interior of the additive blank and the interface of the dissimilar materials by forging the homogenized dissimilar material blank as a whole, improves the additive structure through forging deformation, forges defects such as pores and cracks in the additive, eliminates the residual stress of the additive, improves the strength of the additive part and eliminates the brittleness of the additive; improves the interface structure of the dissimilar materials through forging deformation, utilizes the interface metal flow to disrupt the interface boundary line, forms an interface structure transition zone, promotes the diffusion of elements on both sides of the interface, improves the uniformity of the structure on both sides of the interface and prevents the sudden change of the structure and mechanical properties at the interface, and at the same time forges defects such as poor bonding at the interface, improves the interface bonding strength, and prevents the interface from becoming a weak performance area of ​​the component.

[0055] This implementation method can realize the integral forming of aluminum alloy components of different materials, shorten the manufacturing cycle, further reduce the weight of components while ensuring that the component's organizational performance meets the standards, liberate the structural and material design ideas of aerospace lightweight components, effectively improve the material-performance matching of aerospace lightweight components, and provide a new direction for the design and preparation of lightweight components for the new generation of spacecraft.

[0056] Specific embodiment 2: This embodiment is different from specific embodiment 1 in that: the transition fillet between the spoke and the rim is R5-R10; the width of the outer ring assembly ring 12 is 15mm-25mm; the outer ring assembly ring 12 and the outer wall of the rim body 11 form an angle of 100°-150°; the thickness of the outer ring assembly ring 12 is t3, t3=t1; the outer surface of the rim body 11 is provided with 5-11 strip reinforcement ribs 13 along the axial direction; the strip reinforcement ribs 13 The thickness is 3mm-10mm; the wheel spoke is composed of 7 Y-shaped thin plates 21, an axle mounting flange 22 and a transition area 23; the outer diameter of the axle mounting flange 22 is D3, D3=(0.3-0.35)D1; the inner diameter of the axle mounting flange 22 is D4, D4=(0.2-0.25)D1; the thickness of the axle mounting flange 22 is t4, t4=(1-3)t2; the axle mounting flange 22 is offset 0mm-15mm along the axial direction of the hub. The rest is the same as the first embodiment.

[0057] Specific implementation method three: This implementation method is a forging-additive-reforging integral forming method of a wheel hub of a manned lunar rover made of one piece of heterogeneous materials, which is carried out in the following steps:

[0058] 1. Blank making:

[0059] Processing a forging blank to obtain a forging blank;

[0060] The forging blank is composed of a wheel rim main body blank and a transition area blank, and the outer edge of the transition area blank is connected to the inner surface of the wheel rim main body blank;

[0061] 2. Forging of rims and transition areas:

[0062] The forging blank and the forging die are lubricated, and then the forging 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 forging blank is placed in the forging die and positioned, and the forging blank is forged at a pressing speed of 2.5 mm / s to 12.8 mm / s, and finally cooled to room temperature in air to obtain a forging;

[0063] The forgings are composed of a wheel rim main body forging and a transition area forging;

[0064] 3. Additive interface finishing:

[0065] An annular groove is machined on the forging in the transition area;

[0066] 4. Additive

[0067] Using the arc wire feeding additive manufacturing method, multiple Y-shaped sheet blanks and internal ring blanks are formed at the annular groove of the transition area forging, and then polished and trimmed to obtain the wheel composite material;

[0068] 5. Homogenization heat treatment:

[0069] Performing a homogenized heat treatment on the wheel composite material, and finally cooling it to room temperature in air to obtain a homogenized wheel composite material;

[0070] 6. Overall forging forming:

[0071] The homogenized wheel composite material and the forging die are lubricated, and then the homogenized wheel composite material is heated to the aluminum alloy forging temperature T3 and kept warm, and the forging die is preheated to the temperature T4, and then the homogenized wheel composite material is placed in the forging die and positioned, and the homogenized wheel composite material 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;

[0072] 7. Time-intensive treatment:

[0073] The wheel final forging is subjected to artificial aging strengthening treatment, and then cooled to room temperature in air to obtain the final forging after aging;

[0074] 8. Machining of wheel parts:

[0075] The wheel final forging after aging treatment is machined to obtain a heterogeneous material one-piece manned lunar rover wheel hub.

[0076] Specific embodiment 4: This embodiment differs from specific embodiment 3 in that: the processing described in step 1 is mechanical processing or upsetting-punching-expansion-ring rolling process; the material of the forging blank described in step 1 is 2xxx series high-strength aluminum alloy; in step 4, 7xxx series ultra-high-strength aluminum alloy is used as the additive raw material; the forging die described in step 2 and step 6 is the same. It is the same as specific embodiment 3.

[0077] Specific embodiment 5: This embodiment is different from specific embodiment 3 or 4 in that: the inner diameter of the annular groove in step 3 is 55% to 70% of the outer diameter of the wheel rim main body forging; the angle of the annular groove is 20° to 40°; the material addition direction in step 4 is single-sided material addition on one side of the annular groove. The rest is the same as specific embodiment 3 or 4.

[0078] Specific embodiment 6: This embodiment is different from any one of specific embodiments 3 to 5 in that: in step 5, the wheel composite material is subjected to homogenization heat treatment for 8h to 24h at a temperature of 475℃ to 482℃; in step 7, the wheel final forging is subjected to artificial aging strengthening treatment for 12h to 24h at a temperature of 120℃ to 160℃; in step 2, T1=T2, and T1=430℃ to 480℃; in step 6, T3=T4, and T3=400℃ to 450℃. Others are the same as specific embodiments 3 to 5.

[0079] Specific implementation method 7: This implementation method is different from any one of specific implementation methods 3 to 6 in that: the height of the rim body blank described in step 1 is 1.1 to 1.15 times the height of the rim body final forging in step 6; the outer diameter of the rim body blank described in step 1 is 0.95 to 1 times the outer diameter of the rim body final forging in step 6; the wall thickness of the rim body blank described in step 1 is 0.9 to 1 times the wall thickness of the rim body final forging in step 6; the thickness of the transition area blank described in step 1 is 3 to 6 times the thickness of the spoke plate final forging in step 6; the inner diameter of the transition area blank described in step 1 is 3.8 to 4.1 times the inner diameter of the annular final forging in step 6; the transition fillet between the rim body blank and the transition area blank is R10 to R20. Others are the same as specific implementation methods 13 to 6.

[0080] Specific implementation eight: This implementation is different from any one of specific implementations three to seven in that: the height of the wheel rim main body forging described in step two is the same as the height of the wheel rim main body final forging in step six; the outer diameter of the wheel rim main body forging described in step two is the same as the outer diameter of the wheel rim main body final forging in step six; the wall thickness of the wheel rim main body forging described in step two is the same as the wall thickness of the wheel rim main body final forging in step six; the thickness of the transition area forging described in step two is the same as the thickness of the spoke plate final forging in step six; the inner diameter of the transition area forging described in step two is 1.5 to 2 times the inner diameter of the annular final forging in step six; the transition fillet between the wheel rim main body forging and the transition area forging is R10 to R20. Others are the same as specific implementations three to seven.

[0081] Specific implementation method 9: This implementation method is different from any one of specific implementation methods 3 to 8 in that: the thickness of the Y-shaped sheet metal blank described in step 4 is 1.5 to 3 times the thickness of the final forging of the web in step 6; the thickness of the material overlap area formed at the joint between the groove and the annular groove of the Y-shaped sheet metal blank described in step 4 is 1.1 to 3 times the thickness of the final forging of the web in step 6; the branch width of the Y-shaped sheet metal blank described in step 4 is 10 mm to 30 mm; the inner diameter of the circular ring blank described in step 4 is 1.2 to 1.4 times the inner diameter of the final forging of the circular ring in step 6. The rest is the same as specific implementation methods 3 to 8.

[0082] Specific embodiment ten: This embodiment differs from any one of specific embodiments three to nine in that: the wheel final forging described in step six is ​​formed by connecting the rim body final forging and the spoke final forging; the spoke final forging is composed of a plurality of final forgings, Y-shaped sheet-like thin plate final forgings, a circular ring final forging and a transition area final forging; a plurality of Y-shaped sheet-like thin plate final forgings and the transition area final forgings constitute the spoke plate final forging; the height of the rim body final forging is (1.2-1.4) H1, the outer diameter is (1.05-1.2) D1, and the wall thickness is (10-35) t1; the thickness of the spoke plate final forging is (3-5) t2; the branch width of the Y-shaped sheet-like thin plate final forging is 25mm-60mm; the transition radius between the rim body final forging and the spoke final forging is R10-R20; the inner diameter of the circular ring final forging is (0.8-0.9) D4. The rest is the same as Specific Embodiments 3 to 9.

[0083] The following examples are used to verify the beneficial effects of the present invention:

[0084] Embodiment 1:

[0085] A wheel hub of a manned lunar rover with an integrated structure of heterogeneous materials, which is formed by connecting a wheel rim and a wheel spoke; the wheel rim is composed of a wheel rim body 11, an outer ring assembly ring 12 and strip reinforcement ribs 13; the wheel rim body 11 is a cylindrical structure; outer ring assembly rings 12 are provided at both ends of the wheel rim body 11; 7 strip reinforcement ribs 13 are axially provided on the outer surface of the wheel rim body 11, and the 7 strip reinforcement ribs 13 are distributed in an annular shape with equal spacing, and both ends of a single strip reinforcement rib 13 are connected to the outer ring assembly ring 12; the wheel spoke is composed of 7 Y-shaped sheet-like thin plates 21, an axle assembly flange 22 and a transition area 23; the 7 Y-shaped sheet-like thin plates 21 are distributed in an annular shape with equal spacing, and one end is connected to the axle assembly flange 22, and the other end is connected to the inner edge of the transition area 23, and the outer edge of the transition area 23 is connected to the inner surface of the wheel rim body 11; the 7 Y-shaped sheet-like thin plates and the transition area 23 constitute a spoke plate;

[0086] The height H1 of the wheel rim body 11 is 176.7 mm, the outer diameter D1 is 515.7 mm, and the wall thickness t1 is 1 mm; the thickness of the spoke plate is t2, t2=3 mm; the angle of the fork of the Y-shaped sheet 21 is 40°, the width of the upper branch is 23 mm, and the width of the lower branch is 40 mm; the inner diameter of the transition area 23 is D2, D2=360 mm to 420 mm; the transition fillet between the spoke and the wheel rim is R5; the width of the outer ring assembly ring 12 is 2 0mm; the outer ring assembly ring 12 forms an angle of 135° with the outer wall of the wheel rim body 11; the thickness of the outer ring assembly ring 12 is t3, t3=1mm; the thickness of the strip reinforcement rib 13 is 5.4mm; the outer diameter of the axle assembly flange 22 is D3, D3=156mm; the inner diameter of the axle assembly flange 22 is D4, D4=126mm; the thickness of the axle assembly flange 22 is t4, t4=5mm; the axle assembly flange 22 is offset by 7.5mm along the axial direction of the wheel hub;

[0087] The material of the wheel rim and the transition area 23 is 2219 aluminum alloy; the material of the seven Y-shaped sheet plates 21 and the axle assembly flange 22 is 7050 aluminum alloy.

[0088] A forging-adding-reforging integral forming method of a wheel hub of a manned lunar rover with one piece of heterogeneous materials is carried out in the following steps:

[0089] 1. Blank making:

[0090] The forging blank is obtained by machining the forging blank;

[0091] The forging blank is composed of a wheel rim main body blank and a transition area blank, the outer edge of the transition area blank is connected to the inner surface of the wheel rim main body blank; the height of the wheel rim main body blank is 255mm, the outer diameter is 557.8mm, and the wall thickness is 30mm; the thickness of the transition area blank is 42mm, and the inner diameter is 446mm; the transition fillet between the wheel rim main body blank and the transition area blank is R20;

[0092] The material of the forging blank is 2219 aluminum alloy;

[0093] 2. Forging of rims and transition areas:

[0094] Spray graphite lubricant on the surface of the forging blank and the forging die, then heat the forging blank to 480°C, and keep it at 480°C for 90 minutes, and preheat the forging die to 480°C, then place the forging blank in the forging die and position it, forge the forging blank at a pressing speed of 2.5 mm / s, and finally cool it to room temperature in air to obtain a forging;

[0095] The forging is composed of a wheel rim main body forging and a transition area forging, the outer edge of the transition area forging is connected to the inner surface of the wheel rim main body forging; the height of the wheel rim main body forging is 227mm, the outer diameter is 559.6mm, and the wall thickness is 33mm; the thickness of the transition area forging is 10mm, and the inner diameter is 188mm; the transition fillet between the wheel rim main body forging and the transition area forging is R20;

[0096] 3. Additive interface finishing:

[0097] An annular groove is machined on the forging in the transition area;

[0098] The inner diameter of the annular groove is 360 mm; the angle of the annular groove is 30°;

[0099] 4. Additives:

[0100] Using 7050 aluminum alloy as additive raw material, arc wire feeding additive manufacturing method was used to form 7 Y-shaped sheet blanks and circular ring blanks at the annular groove of the transition area forging, and then polished and trimmed to obtain wheel composite materials;

[0101] The thickness of the Y-shaped sheet blank is 25 mm, and the thickness of the material overlap area formed by the butt joint between the groove and the annular groove of the Y-shaped sheet blank is 18 mm; the width of the upper branch of the Y-shaped sheet blank is 18 mm, and the width of the lower branch is 40 mm; the inner diameter of the annular blank is 150 mm;

[0102] 5. Homogenization heat treatment:

[0103] The wheel composite material was subjected to homogenization heat treatment at 475°C for 8 hours, and finally cooled to room temperature in air to obtain a homogenized wheel composite material;

[0104] 6. Overall forging forming:

[0105] The homogenized wheel composite material and the forging die are lubricated, and then the homogenized wheel composite material is heated to the aluminum alloy forging temperature of 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 homogenized wheel composite material is placed in the forging die and positioned. At a pressing speed of 2.5 mm / s, the homogenized wheel composite material is forged as a whole, and finally quickly cooled to room temperature, and the flash is removed to obtain the final wheel forging;

[0106] The wheel final forging is formed by connecting the wheel rim main body final forging and the spoke final forging; the spoke final forging is composed of 7 Y-shaped sheet-like thin plate final forgings, a ring final forging and a transition area final forging; the 7 Y-shaped sheet-like thin plate final forgings and the transition area final forging constitute the spoke plate final forging;

[0107] The height of the wheel rim body final forging is 227mm, the outer diameter is 559.6mm, and the wall thickness is 33mm; the thickness of the spoke plate final forging is 10mm; the width of the upper branch of the Y-shaped sheet plate final forging is 34mm, and the width of the lower branch is 57mm; the transition fillet between the wheel rim body final forging and the spoke final forging is R20; the inner diameter of the annular final forging is 110mm;

[0108] 7. Time-intensive treatment:

[0109] The wheel final forging is subjected to artificial aging strengthening treatment at a temperature of 120°C for 24 hours, and then cooled to room temperature in air to obtain the final forging after aging;

[0110] 8. Machining of wheel parts:

[0111] The wheel final forging after aging treatment is machined to obtain a heterogeneous material one-piece manned lunar rover wheel hub.

[0112] In step 4, the direction of material addition is single-sided material addition on one side of the annular groove.

[0113] Step 2 is the same as the forging die described in step 6.

[0114] Figure 3 This is a flow chart of the forging-addition-reforging integral forming of a wheel hub of a manned lunar rover made of one piece of heterogeneous materials in Example 1;

[0115] Figure 4 It is a schematic diagram of the longitudinal section of the die bore of the forging die described in step 2 and step 6 of embodiment 1;

[0116] Figure 5 It is the finite element simulation result of the forging process in step 2 of embodiment 1, a is the strain cloud diagram before forging, and b is the strain cloud diagram after forging; it can be seen from the figure that the main deformation in the forging process is concentrated in the transition area between the rim and the spoke, the deformation in this area is sufficient, and it has higher performance after heat treatment. At the same time, the rim is fully formed without forging defects.

[0117] Figure 6 This is a schematic diagram of machining an annular groove in step three of embodiment 1, where A is the annular groove.

[0118] Figure 7Schematic diagram of the interface position of the additive material in step 4 of Example 1, a is a schematic diagram of preparing a wheel composite material, in which A is the interface position of the additive material, and b is an enlarged view of position A in a;

[0119] Figure 8 : The finite element simulation results of the overall forging process in step six of Example 1, a is the strain cloud diagram before forging, and b is the strain cloud diagram after forging; it can be seen from the figure that after the overall forging, the metals in the additive area and the composite material interface position have undergone significant deformation and metal flow, which can effectively improve the additive organization and interface bonding strength.

[0120] Fig. 9 This is a finite element analysis diagram of the load condition of the heterogeneous material integrated manned lunar rover wheel hub prepared in Example 1, where a is the deformation under load and b is the stress condition of the wheel under load. It can be seen from the figure that the structural design of the heterogeneous material integrated wheel hub of the embodiment can significantly reduce the stress concentration at the spokes, improve the load-bearing capacity of the wheel at the same weight, and at the same time improve the stiffness at the rim, reduce the deformation of the rim under load, and effectively prevent the premature failure of the wheel due to vibration and friction during service.

Claims

1. A wheel hub of a manned lunar rover made of one piece of heterogeneous materials, characterized in that It is formed by connecting a wheel rim and a wheel spoke; the wheel rim is composed of a wheel rim body (11), an outer ring assembly ring (12) and strip reinforcement ribs (13); the wheel rim body (11) is a cylindrical structure; both ends of the wheel rim body (11) are provided with outer ring assembly rings (12); a plurality of strip reinforcement ribs (13) are axially arranged on the outer surface of the wheel rim body (11), and the plurality of strip reinforcement ribs (13) are distributed in a ring shape with equal spacing, and both ends of a single strip reinforcement rib (13) are connected to the outer ring assembly ring. The wheel spokes are composed of a plurality of Y-shaped thin plates (21), an axle mounting flange (22) and a transition region (23); the plurality of Y-shaped thin plates (21) are distributed in a ring shape at equal intervals, one end of the Y-shaped thin plates is connected to the axle mounting flange (22), the other end is connected to the inner edge of the transition region (23), and the outer edge of the transition region (23) is connected to the inner surface of the wheel rim body (11); the plurality of Y-shaped thin plates and the transition region (23) constitute a spoke plate; The height H1 of the wheel rim body (11) is 150 mm to 250 mm, the outer diameter D1 is 500 mm to 600 mm, and the wall thickness t1 is 1 mm to 3 mm; the thickness of the spoke is t2, t2=(2 to 4)t1; the angle of the fork of the Y-shaped sheet (21) is 30° to 60°, and the width of the branch is 15 mm to 50 mm; the inner diameter of the transition area (23) is D2, D2=(0.7 to 0.85)D1; The material of the wheel rim and the transition area (23) is 2xxx series aluminum alloy material; the material of the plurality of Y-shaped sheet-like thin plates (21) and the axle assembly flange (22) is 7xxx series aluminum alloy material.

2. The heterogeneous material integrated manned lunar rover wheel hub according to claim 1, characterized in that The transition fillet between the spoke and the rim is R5-R10; the width of the outer ring assembly ring (12) is 15mm-25mm; the outer ring assembly ring (12) and the outer wall of the rim body (11) form an angle of 100°-150°; the thickness of the outer ring assembly ring (12) is t3, t3=t1; the outer surface of the rim body (11) is provided with 5-11 strip reinforcement ribs (13) along the axial direction; the thickness of the strip reinforcement ribs (13) is 3mm-10mm; The wheel spokes are composed of 7 Y-shaped thin plates (21), an axle mounting flange (22) and a transition area (23); the outer diameter of the axle mounting flange (22) is D3, D3 = (0.3-0.35) D1; the inner diameter of the axle mounting flange (22) is D4, D4 = (0.2-0.25) D1; the thickness of the axle mounting flange (22) is t4, t4 = (1-3) t2; the axle mounting flange (22) is offset 0 mm to 15 mm along the axial direction of the wheel hub.

3. The forging-adding-reforging integral forming method of a wheel hub of a manned lunar rover made of one piece of heterogeneous materials as claimed in claim 1, characterized in that It is carried out in the following steps:

1. Blank making: Processing a forging blank to obtain a forging blank; The forging blank is composed of a wheel rim main body blank and a transition area blank, and the outer edge of the transition area blank is connected to the inner surface of the wheel rim main body blank; 2. Forging of rims and transition areas: The forging blank and the forging die are lubricated, and then the forging 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 forging blank is placed in the forging die and positioned, and the forging blank is forged at a pressing speed of 2.5 mm / s to 12.8 mm / s, and finally cooled to room temperature in air to obtain a forging; The forgings are composed of a wheel rim main body forging and a transition area forging; 3. Additive interface finishing: An annular groove is machined on the forging in the transition area; 4. Additive Using the arc wire feeding additive manufacturing method, multiple Y-shaped sheet blanks and internal ring blanks are formed at the annular groove of the transition area forging, and then polished and trimmed to obtain the wheel composite material; 5. Homogenization heat treatment: Performing a homogenized heat treatment on the wheel composite material, and finally cooling it to room temperature in air to obtain a homogenized wheel composite material; 6. Overall forging forming: The homogenized wheel composite material and the forging die are lubricated, and then the homogenized wheel composite material is heated to the aluminum alloy forging temperature T3 and kept warm, and the forging die is preheated to the temperature T4, and then the homogenized wheel composite material is placed in the forging die and positioned, and the homogenized wheel composite material 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 final wheel forging; 7. Time-intensive treatment: The wheel final forging is subjected to artificial aging strengthening treatment, and then cooled to room temperature in air to obtain the final forging after aging; 8. Machining of wheel parts: The wheel final forging after aging treatment is machined to obtain a heterogeneous material one-piece manned lunar rover wheel hub.

4. The forging-adding-reforging integral forming method of a wheel hub of a manned lunar rover made of one piece of heterogeneous materials according to claim 3 is characterized in that The processing described in step one is mechanical processing or upsetting-punching-expansion-ring rolling process; the material of the forging blank described in step one is 2xxx series high-strength aluminum alloy; in step four, 7xxx series ultra-high-strength aluminum alloy is used as the additive raw material; the forging mold described in step two and step six is ​​the same.

5. The forging-adding-reforging integral forming method of a wheel hub of a manned lunar rover made of one piece of heterogeneous materials according to claim 3 is characterized in that The inner diameter of the annular groove described in step three is 55% to 70% of the outer diameter of the wheel rim main body forging; the angle of the annular groove is 20° to 40°; and the direction of material addition in step four is single-sided material addition on one side of the annular groove.

6. The forging-adding-reforging integral forming method of a wheel hub of a manned lunar rover made of one piece of heterogeneous materials according to claim 3 is characterized in that In step 5, the wheel composite material is subjected to homogenization heat treatment at a temperature of 475°C to 482°C for 8h to 24h; in step 7, the wheel final forging is subjected to artificial aging strengthening treatment at a temperature of 120°C to 160°C for 12h to 24h; in step 2, T1=T2, and T1=430°C to 480°C; in step 6, T3=T4, and T3=400°C to 450°C.

7. The forging-adding-reforging integral forming method of a wheel hub of a manned lunar rover made of one piece of heterogeneous materials according to claim 3 is characterized in that The height of the wheel rim body blank described in step one is 1.1 to 1.15 times the height of the wheel rim body final forging in step six; the outer diameter of the wheel rim body blank described in step one is 0.95 to 1 times the outer diameter of the wheel rim body final forging in step six; the wall thickness of the wheel rim body blank described in step one is 0.9 to 1 times the wall thickness of the wheel rim body final forging in step six; the thickness of the transition area blank described in step one is 3 to 6 times the thickness of the spoke plate final forging in step six; the inner diameter of the transition area blank described in step one is 3.8 to 4.1 times the inner diameter of the ring final forging in step six; the transition radius between the wheel rim body blank and the transition area blank is R10 to R20.

8. The forging-adding-reforging integral forming method of a wheel hub of a manned lunar rover made of one piece of heterogeneous materials according to claim 3 is characterized in that The height of the wheel rim main body forging described in step 2 is the same as the height of the wheel rim main body final forging described in step 6; the outer diameter of the wheel rim main body forging described in step 2 is the same as the outer diameter of the wheel rim main body final forging described in step 6; the wall thickness of the wheel rim main body forging described in step 2 is the same as the wall thickness of the wheel rim main body final forging described in step 6; the thickness of the transition area forging described in step 2 is the same as the thickness of the spoke plate final forging described in step 6; the inner diameter of the transition area forging described in step 2 is 1.5 to 2 times the inner diameter of the annular final forging described in step 6; the transition fillet between the wheel rim main body forging and the transition area forging is R10 to R20.

9. The forging-adding-reforging integral forming method of a wheel hub of a manned lunar rover made of one piece of heterogeneous materials according to claim 3 is characterized in that The thickness of the Y-shaped sheet metal blank described in step 4 is 1.5 to 3 times the thickness of the final forging of the spoke plate in step 6; the thickness of the material overlapping area formed at the joint of the groove and the annular groove of the Y-shaped sheet metal blank described in step 4 is 1.1 to 3 times the thickness of the final forging of the spoke plate in step 6; the branch width of the Y-shaped sheet metal blank described in step 4 is 10 mm to 30 mm; the inner diameter of the circular ring blank described in step 4 is 1.2 to 1.4 times the inner diameter of the circular ring final forging in step 6.

10. The forging-adding-reforging integral forming method of a wheel hub of a manned lunar rover made of one piece of heterogeneous materials according to claim 3 is characterized in that The wheel final forging described in step six is ​​formed by connecting the rim body final forging and the spoke final forging; the spoke final forging is composed of multiple Y-shaped sheet-like thin plate final forgings, annular ring final forgings and transition area final forgings; multiple Y-shaped sheet-like thin plate final forgings and transition area final forgings constitute the spoke plate final forging; the height of the rim body final forging is (1.2-1.4) H1, the outer diameter is (1.05-1.2) D1, and the wall thickness is (10-35) t1; the thickness of the spoke plate final forging is (3-5) t2; the branch width of the Y-shaped sheet-like thin plate final forging is 25mm-60mm; the transition radius between the rim body final forging and the spoke final forging is R10-R20; the inner diameter of the annular ring final forging is (0.8-0.9) D4.

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