Titanium alloy shackle and machining method thereof

Abstract

The invention relates to a titanium alloy shackle and a processing method thereof, TC4 titanium alloy powder, glass fiber and Ti3AlC2 powder are mixed and pressed and then are subjected to cold isostatic pressing, vacuum sintering and multi-pass extrusion forming, and the material performance is optimized through heat treatment. A shackle body and transverse pin assembly is manufactured through forging, bending, shaping and numerical control machining of a formed bar, reinforcing parts are arranged at the two ends of the shackle body, a shaft hole is formed in one end of a transverse pin, and the transverse pin is hinged to the reinforcing parts through a rotating shaft to achieve rotation. The first reinforcing part is provided with a self-locking structure which comprises a duckbilled push rod, a limiting shaft, a limiting clamping groove and a locking sliding block, and reliable locking is achieved through cooperation of a ratchet wheel and a stop pawl. The titanium alloy shackle provided by the invention has the characteristics of high strength, corrosion resistance, self-locking safety, excellent surface quality and the like, and is suitable for high-frequency connection scenes.

Description

Technical Field

[0001] The invention belongs to the technical field of engineering equipment, and in particular relates to a titanium alloy shackle and a processing method thereof. Background Art

[0002] A shackle is a commonly used connection tool, which usually consists of a metal cross-pin body with a curved shape and a cross-pin. The design of the shackle allows it to securely connect two items, such as wire ropes, chains or rigging, and can be easily opened and closed. The materials currently used to make shackles are steel and aluminum alloys. For example, carbon steel shackles have high tensile strength and yield strength, are low-cost and suitable for general lifting and handling operations; alloy steel shackles have higher strength and toughness, and are suitable for heavy loads and high-intensity operations; aluminum alloy shackles are lightweight and have good corrosion resistance in humid and salt spray environments.

[0003] Patent ZL200620124095.9 discloses a die-forging method for steel shackles. The curved section of the shackle body has an I-shaped cross-section, which can increase the rated load capacity by 20%. However, the I-shaped design increases the overall weight and, in actual use, can lead to stress concentration under load. Patent CN218718510U discloses an alloy steel U-shaped shackle structure, which offers the advantages of being less susceptible to thread damage and easy to disassemble. However, the heavy alloy steel increases handling and labor intensity during installation. Patent CN207777528U discloses a high-strength wide-body shackle. After heat treatment, the shackle exhibits high strength and toughness, allowing it to connect two or more steel ropes. While heat treatment enhances strength and toughness, its performance can be affected in corrosive environments. Patent CN221603157U discloses a shackle forging device that allows for quick and convenient removal of the forged shackle, reducing operator workload and improving work efficiency. However, this device is only applicable to specific types of shackles, has high manufacturing costs, and increases production preparation time.

[0004] With the development of technology, the research on shackles is not only limited to the optimization of structural design, but also improves the overall performance of shackles through material improvements. Li Xiujie studied the failure behavior of 45 steel shackles during lifting. The results showed that the surface of 45 steel shackles is prone to defects, and the uneven distribution of microstructure and coarse grains are the main reasons for the fracture of shackles under load. Wang Ming studied the application of 42CrMo alloy steel shackles in heavy industry. The results showed that alloy steel shackles have high strength and corrosion resistance, but their cost is high and they are difficult to process. Zhang Qiang analyzed the performance of 316L stainless steel shackles in marine engineering and found that they have excellent corrosion resistance, but their cost is high and their strength is insufficient in high-intensity operations. Zhao Li explored the application of 7075-T6 aluminum alloy shackles in aerospace, which meets the lightweight requirements in aircraft assembly, but their strength is low and the surface is easily damaged.

[0005] It can be seen that traditional shackles are mostly made of carbon steel or stainless steel. Although the cost is low, they are prone to rust in highly corrosive environments such as the ocean and chemical industry, and are heavy, which is not conducive to improving operating efficiency. Summary of the Invention

[0006] The purpose of the embodiment of the present invention is to provide a titanium alloy shackle, which solves the problem that the corrosion resistance and strength of traditional titanium alloy shackles are difficult to match in corrosive environments.

[0007] A second objective of an embodiment of the present invention is to provide a method for processing a titanium alloy shackle.

[0008] In order to solve the above technical problems, the technical solution adopted by the present invention is a method for processing a titanium alloy shackle, comprising the following steps:

[0009] S1, mixing TC4 titanium alloy powder, glass fiber, and Ti3AlC2 powder and pressing; after the pressing is completed, vacuum sintering and cutting to obtain a rod; then extruding the rod;

[0010] S2, forging the first and second square reinforcement portions at both ends of the extruded bar, and then applying pressure to the bar through a bending device;

[0011] S3, placing the bar material processed in S2 into a shaping die to form a shackle body; directly placing the bar material obtained in S2 into a cross pin die for extrusion, and obtaining a titanium alloy cross pin through mechanical processing; finally, using a CNC machine tool to machine corresponding holes on the first reinforcement part and the second reinforcement part of the shackle body, and providing a self-locking structure on the first reinforcement part; after assembly, a titanium alloy shackle is obtained;

[0012] S4. Chemically polishing the titanium alloy shackle obtained in S3.

[0013] Furthermore, the TC4 titanium alloy powder, glass fiber, and Ti3AlC2 powder described in S1 are mixed in a mass ratio of 70-80:10-15:10-15; wherein the particle size of the TC4 titanium alloy powder is 10-30 μm, the diameter of the glass fiber is 1-7 μm, and the particle size of the Ti3AlC2 powder is 1-5 μm.

[0014] Furthermore, the pressing in S1 is specifically cold isostatic pressing, and the pressing pressure is 400-600 MPa.

[0015] Furthermore, the specific process of vacuum sintering in S1 is as follows: first, remove the air until the vacuum degree is 10 -1 Pa, and then raised to a vacuum degree of 10 -3 The rods were sintered at 1200-1400°C at a heating rate of 5-10°C / min and kept at this temperature for 2-4 hours. Subsequently, in a vacuum environment of ≤10-2Pa, a 30-60kV electron beam was used to scan and melt the rods. The moving speed of the melting zone was set at 0.5-5mm / min and the width of the melting zone was set at 3-8mm. Finally, the rods were cooled to 600-700°C in the furnace and then cooled naturally.

[0016] Furthermore, the heat treatment temperature in S2 is 700-800° C. and the heat preservation time is 1.5-2 hours.

[0017] Furthermore, the specific process of medium-diameter angular extrusion of S3 is to extrude the rods obtained by S3 through three different sets of equal-diameter angular extrusion dies in sequence at 550–600 °C at 2 mm / s using a punch;

[0018] The three groups of equal channel angular extrusion dies each include a first module, a second module, and an internal channel; the internal channel includes a die angle; the die angles of the three groups of dies are 135°, 90°, and 60°, respectively; the equal channel angular extrusion die material is Cr 12 MoV, hardness is 55~58HRC.

[0019] Furthermore, the specific process of S6 is to place the titanium alloy shackle in a mixed solution of 3% to 5% by mass hydrofluoric acid, 20% to 30% by mass nitric acid and the balance deionized water, and treat it at 30±2° C. for 30 to 120 seconds with ultrasonic-assisted stirring;

[0020] Next, the titanium alloy shackle is neutralized with alkaline solution and rinsed with deionized water before passivation treatment. The passivation treatment process is as follows: the rinsed titanium alloy shackle is passivated in a mixed solution of 5% to 6% nitric acid by mass, 1% to 2% hydrogen peroxide by mass and the remainder deionized water for 10 to 15 minutes, and the temperature during the passivation process is 50 to 60°C.

[0021] A titanium alloy shackle, comprising a shackle body and a titanium alloy cross pin, wherein the ends of the shackle body are respectively provided with a first reinforcement portion and a second reinforcement portion, and the first reinforcement portion and the second reinforcement portion are respectively provided with an arched through groove in the connecting direction;

[0022] The titanium alloy cross pin has one end with the same diameter as the shackle body, and the other end with a smaller diameter than the shackle body and provided with an axial hole; it also includes a rotating shaft, which passes through the axial hole to hinge the titanium alloy cross pin with the second reinforcement part so that the titanium alloy cross pin can rotate around the rotating shaft; the first reinforcement part is provided with a self-locking structure.

[0023] Furthermore, the self-locking structure includes:

[0024] A duckbill push rod is disposed inside the first reinforcement portion, one end of the duckbill push rod is a duckbill protrusion structure that passes through the surface of the first reinforcement portion and extends into the through groove of the first reinforcement portion, and the difference between the length of the protrusion and the width of the through groove is less than the diameter of the titanium alloy cross pin, and the other end is a ratchet structure;

[0025] A limiting shaft, wherein a shaft key is provided at the center of the limiting shaft, the limiting shaft passes through the first reinforcement portion and is parallel to the line connecting the first reinforcement portion and the second reinforcement portion, and bearings are provided at both ends of the limiting shaft; a through hole with a shaft key groove is provided at the center of the ratchet structure of the duckbill push rod, and the duckbill push rod is nested in the limiting shaft through the through hole and cooperates with the shaft key;

[0026] A limiting slot is provided on the surface of the first reinforcement portion and corresponds to and remains parallel to the limiting axis;

[0027] The locking slider is arranged in the limit slot, and a stopping pawl is provided at the bottom of the locking slider, and the stopping pawl is in the opposite direction to the ratchet groove of the duckbill push rod.

[0028] Furthermore, the width of the stopping pawl is smaller than the projected distance from the edge of the limiting slot to the duckbill push rod.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention adopts titanium alloy as the base material to introduce reinforcing phases such as MAX phase (Ti3AlC2) and glass fiber into the material, so as to achieve uniform distribution thereof in the matrix, give full play to the multi-phase synergistic reinforcement effect, obtain a fully dense composite structure, and significantly improve the mechanical properties of the material. Subsequently, the material is subjected to a strong plastic deformation treatment through an equal-diameter angular extrusion process to refine the surface grains, thereby improving the strength and toughness of the material and effectively preventing brittle fracture during use. The overall design of the shackle is an arc structure to avoid stress concentration, reduce the risk of defects, extend the service life, and facilitate processing and forming, and reduce manufacturing costs. A rotating shaft structure is provided at one end to facilitate quick connection and disassembly, reduce friction and torque, and improve operational convenience and durability; at the same time, it is equipped with a self-locking mechanism that can be operated with one hand to prevent accidental opening under stress, ensure operational safety, and is suitable for frequent loading and unloading occasions. Finally, through chemical polishing treatment, a dense passivation film layer is formed while improving the surface quality to enhance corrosion resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0031] Figure 1 The structure diagram of the equal diameter angular extrusion die of this embodiment, (a) is a first-stage step-reducing extrusion die, (b) is a second-stage step-reducing extrusion die, (c) is a third-stage step-reducing extrusion die

[0032] Figure 2 This is the extruded rod after equal-diameter angular extrusion in this embodiment

[0033] Figure 3 This is the preliminary shackle body after preliminary forging in this embodiment;

[0034] Figure 4 It is the bending equipment of this embodiment;

[0035] Figure 5 This is a diagram of the cross pin mold in this embodiment;

[0036] Figure 6 It is the self-locking device of this embodiment;

[0037] Figure 7 is a schematic diagram of a titanium alloy cross pin in this embodiment;

[0038] Figure 8 This is a schematic diagram of the unlocked state of the titanium alloy cross pin of the shackle of this embodiment;

[0039] Figure 9 is a top view of the self-locking device of this embodiment;

[0040] Figure 10 Schematic diagram of the duckbill push rod and locking slider structure of the self-locking device of this embodiment; wherein (a) is the duckbill push rod, and (b) is the locking slider;

[0041] Figure 11 This is the closed state intention of the titanium alloy cross pin of the shackle of this embodiment;

[0042] Figure 12 The microstructure of titanium alloy composite materials before and after equal channel angular extrusion; (a) is before extrusion; (b) is after extrusion.

[0043] In the figure, 1. punch; 2. rod; 3. first module; 4. second module; 5. hydraulic pump; 6. frame; 7. ring die; 8. clamping device; 9. cross pin upper die; 10. cross pin lower die; 11. titanium alloy cross pin; 12. rotating shaft; 13. first reinforcement part; 14. duckbill push rod; 15. locking slider; 16. limit slot; 17. shaft hole; 18. second reinforcement part; 19. shackle body; 20. bearing; 21. limit shaft; 22. shaft keyway; 23; stop pawl. DETAILED DESCRIPTION

[0044] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0045] Although traditional titanium alloy materials are widely used in various harsh environments due to their excellent corrosion resistance, in actual engineering applications, their mechanical strength is often difficult to meet the requirements of high-intensity working conditions. Therefore, when using titanium alloys in load-bearing components such as shackles, it is necessary to take into account both the high strength of the material and its original excellent corrosion resistance. This requires that the selected titanium alloy material can maintain good environmental tolerance while improving mechanical properties to ensure structural safety and service life. This embodiment provides a titanium alloy shackle for ship lifting operations, such as Figure 9 This shackle is suitable for connecting slings to cargo, securing cables, and other applications. It is designed to ensure the stability and safety of ships under various working conditions and has excellent engineering application value and reliability.

[0046] like Figures 6-11The shackle includes a U-shaped shackle body 19, and a first reinforcement part 13 and a second reinforcement part 18 are respectively provided at its two ends to enhance the structural strength and provide connection and self-locking functions. Arched through grooves are provided on the first reinforcement part 13 and the second reinforcement part 18. The shackle also includes a titanium alloy cross pin 11, the diameter of one end of the titanium alloy cross pin 11 is the same as the diameter of the shackle body 19, and the diameter of the other end is smaller than the diameter of the shackle body 19; an axial hole 17 is provided at the end with a smaller diameter of the titanium alloy cross pin 11. A rotating shaft 12 is also provided on the second reinforcement part 18, and the rotating shaft 12 passes through the axial hole 17 on the titanium alloy cross pin 11 to realize a hinged connection between the titanium alloy cross pin 11 and the second reinforcement part 18, so that the titanium alloy cross pin 11 can rotate around the rotating shaft 12 and rotate relative to the second reinforcement part 18, thereby realizing a large-angle swing function. A self-locking structure is provided on the first reinforcement portion 13. The self-locking structure primarily comprises a duckbill push rod 14, a locking slider 15, a limiting slot 16, a bearing 20, and a limiting shaft 21. The self-locking structure is made of the composite material of the shackle body 19 of this embodiment. The limiting slot 16 is provided on the surface of the first reinforcement portion 13; below the limiting slot 16, a duckbill push rod 14 is provided within the first reinforcement portion 13. One end of the duckbill push rod 14 is a duckbill-shaped protrusion that extends through the surface of the first reinforcement portion 13 and into the through-slot of the first reinforcement portion 13. The difference between the length of the protrusion and the width of the through-slot is less than the diameter of the titanium alloy cross pin 11. The other end of the push rod 14 is a ratchet structure; the ratchet and the stop pawl 23 are in opposite directions. The stopping pawl 23 is arranged at the bottom of the locking slider 15, and the locking slider 15 is arranged in the limiting slot 16 of the first reinforcement part 13. The limiting slot 16 is parallel to the limiting shaft 21 and is arranged correspondingly; the center of the limiting shaft 21 is provided with an axis key, and the limiting shaft 21 is arranged through the first reinforcement part 13; the direction of the limiting shaft 21 is parallel to the direction of the connection between the first reinforcement part 13 and the second reinforcement part 18, and the two ends of the limiting shaft 21 in contact with the first reinforcement part 13 are provided with bearings 20, and the center of the ratchet structure of the duckbill push rod 14 is provided with a through hole with an axis keyway, and the duckbill push rod 14 is nested on the limiting shaft 21 and cooperates with the axis key; the width of the stopping pawl 23 is smaller than the projection distance from the edge of the limiting slot 16 to the duckbill push rod 14. When the duckbill push rod 14 moves to the two ends of the limit slot 16, the duckbill push rod 14 can rotate freely with the limit shaft 21, and the duckbill push rod 14 is in a completely loosened state. At this time, the titanium alloy cross pin 11 can fall into the first reinforcement part 13 at the end of the shackle body 19; when the locking slider 15 moves to the center of the limit slot 16, the stopping pawl 23 is inserted into the ratchet tooth groove at the other end of the duckbill push rod 14, and the duckbill push rod 14 is closed, thereby preventing the titanium alloy cross pin 11 from detaching from the shackle body 19, realizing the self-locking function.

[0047] In some possible implementations, the maximum diameter of the titanium alloy cross pin 11 is equal to the diameter of the shackle body 19 .

[0048] This embodiment also provides a method for processing a titanium alloy shackle, which is specifically performed according to the following steps:

[0049] S1. Material preparation. In order to meet the requirements of high strength and corrosion resistance of shackles in applications, TC4 titanium alloy powder (particle size of 10-30 μm), glass fiber (diameter of 1-7 μm) and Ti3AlC2 (particle size of 1-5 μm) are selected and uniformly mixed in a mass ratio of 70-80:10-15:10-15. If the amount of titanium alloy is too little and the reinforcing phase is too much, the toughness of the material is difficult to guarantee and brittle fracture is prone to occur, which is absolutely not allowed in shackles. If the amount of titanium alloy is too much and the reinforcing phase is too little, it is difficult to play a strengthening role, resulting in insufficient strength of the titanium alloy, deformation during use and premature failure; then, the mixed material is pressed into a green billet with a length of not less than 30 mm and a diameter of not less than 20 mm by cold isostatic pressing at a pressure of 400-600 MPa. Next, the pressed green body is vacuum sintered: first, most of the gas is removed by low vacuum (10-1Pa), and then sintered by high vacuum (10-3Pa); the temperature is raised to 1200-1400℃ at a heating rate of 5-10℃ / min; and the temperature is kept for 2-4 hours to achieve particle bonding. Subsequently, in a vacuum environment of ≤10-2Pa, a 30-60kV electron beam is used to locally scan and melt the sintered blank. The melting zone movement speed is set to 0.5-5mm / min and the melting zone width is 3-8mm. High energy is used for rapid heating, melting and solidifying at the same time. Finally, it is cooled to 600-700℃ in the furnace and then cooled naturally. It is then turned (carbide tool, 30-60m / min cutting speed) into the target size bar 2; then the target size bar 2 is extruded, and the diameter of the initial bar 2 is prepared according to formula (1) to ensure that the corresponding deformation amount is met during the subsequent extrusion process, thereby obtaining a titanium alloy shackle that meets the synergistic improvement of strength and corrosion resistance.

[0050] Rod 2 diameter = K1 × K2 × K3 × g (1)

[0051] Wherein, K1=1.1, K2=1.3, K3=1.4 (K is a parameter index obtained according to the deformation of the extrusion die, K1, k2, k3 are obtained according to the deformation of the extrusion die, and the diameter of the initial rod 2 used is prepared according to the required diameter of the rod 2 to ensure that the corresponding deformation is met in the subsequent extrusion process), and g represents the design diameter of the shackle body 19 or the titanium alloy cross pin 11.

[0052] Example 1

[0053] TC4 titanium alloy powder with a particle size of 20μm, glass fiber with a diameter of 4μm, and Ti3AlC2 with a particle size of 3μm were uniformly mixed in a mass ratio of 75:12:12. The mixture was then pressed into a green compact using cold isostatic pressing at a pressure of 500MPa. Next, the compact was sintered at a heating rate of 7°C / min to 1300°C and held at this temperature for 3 hours to achieve particle bonding. Subsequently, the sintered compact was locally scan-melted using a 40kV electron beam in a vacuum environment of ≤10-2Pa. The melt zone was set at a speed of 2.5mm / min and a width of 5mm. High-energy rapid heating was used to achieve simultaneous melting and solidification. Finally, the compact was furnace-cooled to 650°C and then naturally cooled. Comparison test results with other materials are shown in Table 2. While maintaining excellent tensile strength and yield strength, the present embodiment exhibited excellent neutral salt spray corrosion resistance, effectively avoiding oxidation corrosion in this environment. Its overall mechanical properties and corrosion resistance surpassed those of the comparative materials.

[0054] Example 2

[0055] The difference from Example 1 is that 10 μm TC4 titanium alloy powder, 1 μm diameter glass fiber, and 1 μm particle size Ti3AlC2 are uniformly mixed in a mass ratio of 70:10:10. The mixed material is then pressed into a green compact by cold isostatic pressing at a pressure of 400 MPa. The green compact is then sintered at a heating rate of 5°C / min to 1200°C for 2 hours. In a vacuum environment of ≤10-2 Pa, the sintered compact is locally scan-melted using a 30 kV electron beam. The melt zone travel speed is set at 0.5 mm / min and the melt zone width is 3 mm. High-energy rapid heating is used to achieve simultaneous melting and solidification. Finally, the green compact is cooled in the furnace to 600°C and then naturally cooled. The remaining steps are the same as in Example 1.

[0056] Example 3

[0057] The difference from Example 1 is that 30 μm TC4 titanium alloy powder, 7 μm diameter glass fiber, and 5 μm particle size Ti3AlC2 are uniformly mixed in a mass ratio of 80:15:15. The mixed material is then pressed into a green compact by cold isostatic pressing at a pressure of 600 MPa. The green compact is then sintered at a heating rate of 10°C / min to 1400°C for 4 hours. In a vacuum environment of ≤10-2 Pa, the sintered compact is locally scan-melted using a 60 kV electron beam. The melt zone travel speed is set at 0.5 mm / min and the melt zone width is 8 mm. High-energy rapid heating is used to achieve simultaneous melting and solidification. Finally, the green compact is furnace-cooled to 700°C and then naturally cooled. The remaining steps are the same as in Example 1.

[0058] S2: Heat treatment: Heat the bar treated in S1 to a temperature range of 700-800°C for 1.5-2 hours to reduce the structural and stress heterogeneity of Bar 2 during the extrusion process, thereby obtaining fine and uniform equiaxed grains. This temperature range is within the α+β two-phase region. Processing within this range can utilize the characteristics of the two phases to achieve more uniform deformation while maintaining good mechanical properties.

[0059] S3, equal channel angular extrusion, using strong plastic deformation to make the surface of the material obtain fine microstructure, while the core maintains the initial organizational state, which is conducive to the material to ensure high strength while also having good plastic toughness. The specific method is to put one end of the bar 2 after heat treatment in step 2 into the equal channel angular extrusion die, and under the extrusion of the punch 1, the bar 2 is sequentially passed through the Figure 1 (a) to (c) show three sets of extrusion dies.

[0060] In some specific embodiments, the three sets of extrusion dies each include a punch 1, a first module 3, and a second module 4, wherein the first module 3 and the second module 4 are assembled to form an extrusion die having a channel structure with a die corner inside. After the rod 2 is extruded and deformed by the three sets of dies in sequence, the following is obtained: Figure 2 The rod 2 shown in the figure. The die size and parameters are shown in Table 1. In order to obtain the shape of the shackle body 19, the rod 2 is sequentially passed through the 550-600 ° C Figure 1 The extrusion die shown.

[0061] Table 1 Die ECA Extrusion Parameters

[0062]

[0063] in, Figure 1 (c) Diameter of the upper end of the channel of the mold f = g × (1 + 10%); Figure 1 (b) The upper end diameter of the channel of the mold is e = f × (1 + 30%); Figure 1 (a) The upper channel diameter of the mold d = e × (1 + 40%). Figure 1 (a) to (c) The three sets of die channel angles Ф are 135, 90, and 60 degrees respectively. The ECA die material is Cr 12 MoV, hardness is 55-58HRC. The bar 2 is formed into a V shape by equal channel angular extrusion with the above parameters. Other shapes can also be obtained by setting the extrusion parameters and the die shape according to the final design requirements.

[0064] Example 4

[0065] The composite material prepared in Example 1 was preheated at 250°C and then subjected to equal channel angular extrusion (ECAP) with die channel angles of 30°, 60°, and 90°, an extrusion speed of 2 mm / s, and three extrusion passes. The sample was rotated 180° after each extrusion pass to obtain a uniform microstructure and excellent mechanical properties. The microstructure of the composite material before and after ECAP is shown in FIG. Figure 12 As shown in (a) and (b), this embodiment significantly refines the grain size of the composite matrix and optimizes the distribution and interfacial bonding of the reinforcing phase (Ti3AlC2), resulting in a more uniform dispersion and reduced size. As shown in Table 2, mechanical property testing shows that the tensile strength of this embodiment is increased from the original 1250 MPa to 1380 MPa (a 10% increase), while the elongation remains above 8.5%. A neutral salt spray test (GB / T 10125) shows that after 720 hours of testing, the corrosion rate is reduced from 0.12 mm / a to 0.05 mm / a (a 58% improvement).

[0066] Table 2 Mechanical properties

[0067]

[0068]

[0069] S4, die forming, the extruded bar 2 obtained in step 3 is placed on the air hammer equipment, and free forging is performed on both ends thereof to form the following Figure 3 The regular rectangular or cube geometric shape is used as the reinforcement part (i.e. the first reinforcement part 13 and the second reinforcement part 18 of the final shackle). The main purpose of the preforming process of this embodiment is to improve the convenience of subsequent machining and assembly operations, and at the same time it is conducive to achieving high-precision alignment and connection with key matching parts such as the titanium alloy cross pin 11, thereby enhancing the assembly accuracy and component interchangeability of the overall structure, ensuring reliable connection and collaborative working performance between various functional components, such as Figure 3 Then, the bar 2 is transferred to the bending equipment, and pressure is applied in a station equipped with a specific shape mold to initially shape the bar 2 into a ring-shaped structure, as shown in FIG. Figure 4As shown; in this embodiment, the shackle body 19 is a hanging ring-shaped structure. If it is necessary to design it into other structural forms according to actual application requirements, the pressure parameters and mold cavity design in the forming process can be adjusted accordingly according to the geometric shape of the final shackle body 19 to achieve the initial shape of the blank. The bending equipment is composed of a frame 6, on the top of which is provided a hydraulic pump 5 for driving the hydraulic hammer installed at the bottom of the hydraulic cylinder to apply a load downward in the vertical direction; the bottom of the frame 6 is provided with a clamping device 8 for fixing the annular die 7, the bottom of the die is provided with an annular groove structure that tapers in the axial direction, and its axis is aligned with the action center of the hydraulic hammer. Through the directional pressure of the hydraulic hammer in the annular die 7, the bar 2 is formed into a geometric configuration with a circular arc transition. The forming method of this embodiment not only helps to reduce the stress concentration effect generated in key parts during service, thereby avoiding early failure behavior caused by excessive local stress during lifting operations, but also is more conducive to the metal flow and forming control of the subsequent die forging process, thereby improving the forming accuracy and material utilization rate.

[0070] S5, shaping, the initially formed ring-shaped rod 2 is placed in the ring-shaped shaping die, and pressurized to form the desired ring-shaped shackle body 19; in this embodiment, the cavity of the shaping die is a ring-shaped structure; according to actual needs, a die with other cavity shapes can also be selected to achieve the forming of shackle bodies 19 of different structural forms. Similarly, the rod 2 obtained in step S1 is placed in the cross pin die for extrusion to obtain the structural dimensions of the desired titanium alloy cross pin 11, such as Figure 5 The cross pin mold includes a cross pin upper mold 9 and a cross pin lower mold 10.

[0071] In some specific embodiments, the cross pin rods are also prepared using the processes of S1 and S2.

[0072] S6: Auxiliary machining: A CNC milling machine is used to machine the end face of the lifting ring and drill a hole. A drilling machine with an indexing head is then used to machine the axial hole 17 of the titanium alloy cross pin 11. Finally, a CNC lathe is used to securely clamp the lifting ring, set the tool path, and then, by rotating the screw and tool, machine the corresponding holes at both ends of the shackle body 19. A self-locking structure is then installed on the first reinforcement 13, and the titanium alloy shackle is assembled. The test results comparing the self-locking shackle of the present invention with a conventional U-shaped shackle are shown in Table 3.

[0073] Table 3 Test performance results

[0074]

[0075] S7, chemical polishing: Place the shackle body 19 and titanium alloy cross pin 11 in a mixed solution of 3% to 5% hydrofluoric acid by mass, 20% to 30% nitric acid by mass, and the balance deionized water at 30±2°C for 30 to 120 seconds with ultrasonic-assisted stirring. Subsequently, neutralize with alkaline solution, rinse with deionized water, and then perform a passivation treatment. The passivation treatment process is as follows: passivate the rinsed titanium alloy shackle in a mixed solution of 5% to 6% nitric acid by mass, 1% to 2% hydrogen peroxide by mass, and the balance deionized water for 10 to 15 minutes at a temperature of 50 to 60°C. Finally, a mirror effect with a surface roughness of Ra 0.2-0.4μm (reflectivity > 85%) is achieved, while the hydrogen content is controlled to be <50ppm. Under these passivation conditions, the generated layer thickness is 5 to 10nm. The corrosion resistance data of the passivation layer are shown in Table 4.

[0076] Table 4 Salt spray test results (simulated body fluid / 3.5% NaCl solution)

[0077]

[0078] Each embodiment in this specification is described in a related manner. Similar parts between the various embodiments can be referred to in conjunction with each other. Each embodiment focuses on the differences between the other embodiments. In particular, the system embodiment is generally similar to the method embodiment, so the description is relatively simple. For related parts, refer to the description of the method embodiment.

[0079] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention are included in the scope of protection of the present invention.

Claims

1. A titanium alloy shackle processing method, characterized in that: The following steps are involved: S1, mixing TC4 titanium alloy powder, glass fiber, and Ti3AlC2 powder and pressing; after the pressing is completed, vacuum sintering and cutting to obtain a rod (2); then extruding the rod; S2, heat treating the extruded rod (2); S3, performing equal-diameter angular extrusion again on the heat-treated rod (2); S4, forging the two ends of the bar material (2) processed in S3 into a square first reinforcement portion (13) and a second reinforcement portion (18), and then press-forming the bar material (2) through a bending device; S5, placing the rod (2) obtained in S4 in a shaping die to form a shackle body (19); directly placing the rod (2) obtained in S2 in a cross pin die for extrusion, and obtaining a titanium alloy cross pin (11) through mechanical processing; finally, using a CNC machine tool to machine corresponding holes on the first reinforcement part (13) and the second reinforcement part (18) of the shackle body (19), and providing a self-locking structure on the first reinforcement part (13); and assembling to obtain a titanium alloy shackle; S6. Chemically polishing the titanium alloy shackle obtained in S5.

2. A titanium alloy shackle processing method according to claim 1, characterized in that: The TC4 titanium alloy powder, glass fiber, and Ti3AlC2 powder described in S1 are mixed in a mass ratio of 70-80:10-15:10-15; wherein the particle size of the TC4 titanium alloy powder is 10-30 μm, the diameter of the glass fiber is 1-7 μm, and the particle size of the Ti3AlC2 powder is 1-5 μm.

3. The method for processing a titanium alloy shackle according to claim 1, characterized in that: The pressing in S1 is specifically cold isostatic pressing, and the pressing pressure is 400 to 600 MPa.

4. A titanium alloy shackle processing method according to claim 1, characterized in that: The specific process of vacuum sintering described in S1 is as follows: first, the air is removed to a vacuum degree of 10-1Pa, and then the vacuum degree is raised to 10-3Pa to sinter the rod (2); the sintering parameters are: heating to 1200-1400°C at a heating rate of 5-10°C / min, and keeping warm for 2-4 hours; then, in an environment of vacuum degree ≤10-2Pa, a 30-60kV electron beam is used to scan and melt the rod (2), and the melting zone movement speed is set to 0.5-5mm / min and the melting zone width is set to 3-8mm; finally, the furnace is cooled to 600-700°C and then cooled naturally.

5. The titanium alloy shackle processing method according to claim 1, characterized in that: The heat treatment temperature in S2 is 700-800°C, and the temperature is kept for 1.5-2h.

6. The method for processing a titanium alloy shackle according to claim 1, characterized in that: The specific process of medium-diameter angular extrusion of S3 is to extrude the rod (2) obtained by S3 through three different sets of equal-diameter angular extrusion dies in sequence at 550-600°C and 2 mm / s using a punch (1); The three groups of equal channel angular extrusion dies each comprise a first module (3), a second module (4) and an internal channel; the internal channel comprises a die angle; the die angles of the three groups of dies are 135°, 90° and 60°, respectively; the material of the equal channel angular extrusion die is Cr 12 MoV, hardness is 55~58HRC.

7. The method for processing a titanium alloy shackle according to claim 1, characterized in that: The specific process of S6 is to place the titanium alloy shackle in a mixed solution of 3% to 5% by mass hydrofluoric acid, 20% to 30% by mass nitric acid and the balance deionized water, and treat it at 30±2°C for 30 to 120 seconds with ultrasonic-assisted stirring; Next, the titanium alloy shackle is neutralized with alkaline solution and rinsed with deionized water before passivation treatment. The passivation treatment process is as follows: the rinsed titanium alloy shackle is passivated in a mixed solution of 5% to 6% nitric acid by mass, 1% to 2% hydrogen peroxide by mass and the remainder deionized water for 10 to 15 minutes, and the temperature during the passivation process is 50 to 60°C.

8. A titanium alloy shackle, comprising a shackle body (19) and a titanium alloy cross pin (11), characterized in that: The ends of the shackle body (19) are respectively provided with a first reinforcement portion (13) and a second reinforcement portion (18), and the first reinforcement portion (13) and the second reinforcement portion (18) are each provided with an arched through groove in the connecting direction; The titanium alloy cross pin (11) has one end with the same diameter as the shackle body (19), and the other end with a smaller diameter than the shackle body (19) and provided with an axial hole (17); it also includes a rotating shaft (12), the rotating shaft (12) passes through the axial hole (17) to hinge the titanium alloy cross pin (11) with the second reinforcement part (18), so that the titanium alloy cross pin (11) can rotate around the rotating shaft (12); the first reinforcement part (13) is provided with a self-locking structure.

9. The titanium alloy shackle according to claim 8, characterized in that: The self-locking structure comprises: A duckbill push rod (14) is arranged inside the first reinforcement part (13), one end of the duckbill push rod (14) is a duckbill protruding structure and passes through the surface of the first reinforcement part (13) and extends into the through groove of the first reinforcement part (13), the difference between the length of the protruding part and the width of the through groove is less than the diameter of the titanium alloy cross pin (11), and the other end is a ratchet structure; A limiting shaft (21), wherein a shaft key is provided at the center of the limiting shaft (21), the limiting shaft (21) passes through the first reinforcement portion (13) and is parallel to the line connecting the first reinforcement portion (13) and the second reinforcement portion (18), and bearings (20) are provided at both ends of the limiting shaft (21); a through hole with a shaft key groove is provided at the center of the ratchet structure of the duckbill push rod (14), and the duckbill push rod (14) is nested on the limiting shaft (21) through the through hole and cooperates with the shaft key; A limiting slot (16), the limiting slot (16) is provided on the surface of the first reinforcement portion (13), and corresponds to and remains parallel to the limiting axis (21); The locking slide block (15) is arranged in the limiting slot (16). A stopping pawl (23) is provided at the bottom of the locking slide block (15). The stopping pawl (23) is in the opposite direction to the ratchet tooth groove of the duckbill push rod (14).

10. The titanium alloy shackle according to claim 9, characterized in that: The width of the stopping pawl (23) is smaller than the projection distance from the edge of the limiting slot (16) to the duckbill push rod (14).

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