A titanium bronze alloy crack repairing method based on friction stir processing and aging cooperation

Abstract

This invention pertains to the remanufacturing and surface repair technology of copper alloy components. It discloses a method for repairing cracks in titanium bronze alloys based on a synergistic approach of friction stir processing (FSP) and aging. The method involves heating the cracked titanium bronze alloy to be repaired to 800-900℃ and holding it at that temperature for 0.5-2 hours, followed by water quenching. The titanium bronze alloy that has undergone solution heat treatment is then repaired using FSP. Finally, the repaired titanium bronze alloy undergoes aging treatment. For the aging treatment, the titanium bronze alloy that has undergone FSP is heated to 400-500℃ and held for 6-8 hours, followed by water cooling. This invention employs a synergistic process of heat treatment, FSP, and subsequent aging, which improves the processing performance of the pre-repaired area, achieves synergistic strengthening through preservation of the ultrafine grain structure and regeneration of nano-precipitates, and restores the performance of the repaired titanium bronze area to the level of the original material.

Description

Technical Field

[0001] This invention pertains to the remanufacturing and surface repair technology of copper alloy components, specifically involving a method for repairing cracks in titanium bronze alloys based on the synergistic effect of friction stir processing and aging. Background Technology

[0002] Titanium bronze alloys (Cu-Ti, Cu-Ti-Fe, Cu-Ti-Cr, etc.) possess high strength, high elasticity, high electrical conductivity, excellent corrosion resistance, and resistance to stress relaxation, making them ideal materials for aerospace elastic structural components, marine engineering and ship corrosion-resistant components, precision molds, and high-temperature wear-resistant special structural components. During long-term service, under the influence of high-temperature gradients, cyclic loads, and media corrosion, microcracks easily develop on the surface of titanium bronze, gradually proliferating and leading to component failure. Therefore, how to quickly and efficiently repair these defects and reduce the cost of repairing high-value thick titanium bronze alloy strips has become a critical issue that urgently needs to be addressed in the current application of titanium bronze alloys.

[0003] Currently, traditional repair methods have obvious drawbacks. Fusion welding, laser cladding, and arc additive manufacturing involve excessive heat input, resulting in a significant heat-affected zone, severe grain coarsening, and a substantial decline in performance. As an age-hardening alloy, titanium bronze can lead to the re-dissolution of precipitates and grain coarsening under high-temperature conditions, resulting in the loss of the strengthening effect. The welding process also results in high residual stress, which can easily lead to deformation, porosity, and hot cracks, making it difficult to guarantee dimensional accuracy.

[0004] To overcome the shortcomings of existing repair technologies, friction stir processing (FSP), as a solid-state processing technique, operates at temperatures below the melting point. It can achieve crack closure, microstructural densification, and grain refinement through intense plastic deformation and dynamic recrystallization, thus avoiding fusion welding defects. However, the FSP process still leads to partial dissolution of precipitated phases in titanium bronze. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, this invention provides a method for repairing cracks in titanium bronze alloys based on the synergistic effect of friction stir processing and aging. This invention employs a synergistic process of heat treatment, FSP, and subsequent aging, which can improve the processing performance of the pre-repair zone, achieve synergistic strengthening by preserving the ultrafine grain structure and regenerating the nano-precipitates, and restore the performance of the titanium bronze repair zone to the level of the parent material.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A method for repairing cracks in titanium bronze alloys based on the synergistic effect of friction stir processing and aging includes the following steps: The titanium bronze alloy with cracks to be repaired is subjected to solution heat treatment. During solution heat treatment, the titanium bronze alloy to be repaired is heated to 800~900℃ and held for 0.5~2 h, followed by water quenching. Friction stir repair was performed on titanium bronze alloys that had undergone solution heat treatment. During the friction stir repair, the stirring pin traveled along the crack path. Aging strengthening treatment was performed on titanium bronze alloys that had undergone friction stir processing to repair cracks in the titanium bronze alloys. During the aging strengthening treatment, the titanium bronze alloys that had undergone friction stir processing were heated to 400~500℃ and held at that temperature for 6~8 hours, followed by water cooling to complete the aging strengthening treatment.

[0007] Preferably, a tungsten-rhenium alloy stirring head is used when performing friction stir repair.

[0008] Preferably, when performing friction stir repair, the diameter of the stirring head is 3~6 mm, the diameter of the shoulder is 12~20 mm, and the length of the stirring pin is matched with the crack depth.

[0009] Preferably, the diameter of the stirring needle is 1.5~3.0 mm.

[0010] Preferably, during friction stir repair, the stirring pin rotates at 600~1200 r / min, travels at 60~100 mm / min, presses down at 0.3~0.5 mm, and tilts at 2°~3°.

[0011] Preferably, the repair method of the present invention further includes a pretreatment process for the titanium bronze alloy with cracks to be repaired, including: surface cleaning, degreasing, and rust removal of the cracked area.

[0012] Preferably, the titanium bronze alloy is made of Cu-Ti alloy, Cu-Ti-Fe alloy, or Cu-Ti-Cr alloy.

[0013] Preferably, in the Cu-Ti alloy, the Ti content is 1.0% to 4.0% by mass, and the balance is Cu.

[0014] Preferably, in the Cu-Ti-Fe alloy, the Ti content is 1.0%~4.0% by mass, the Fe content is 0.15%-0.25%, and the balance is Cu.

[0015] Preferably, in the Cu-Ti-Cr alloy, the Ti content is 1.0%~4.0% by mass, the Cr content is 0.15%-0.25%, and the balance is Cu.

[0016] The present invention has the following beneficial effects: This invention is based on a method for repairing cracks in titanium bronze alloys through the synergistic combination of friction stir processing and aging. By combining solution heat treatment, friction stir processing, and aging strengthening treatment, it effectively solves the existing problems in repairing cracks in titanium bronze alloys. Its innovation lies in the rational arrangement and complementary mechanisms of each process, and the fact that the order of solution heat treatment and aging strengthening treatment cannot be interchanged, which is a key prerequisite for ensuring the repair effect. Specifically, this invention first heats the cracked titanium bronze alloy to be repaired to 800–900°C, holds it at that temperature for 0.5–2 hours, and then quenches it in water to complete the solution heat treatment. This treatment not only allows the original strengthening precipitates inside the alloy to fully dissolve into the matrix, achieves composition homogenization, and releases internal stress, preventing further crack propagation during the repair process, but also significantly improves the plasticity of the area to be repaired, laying a good foundation for subsequent friction stir processing (FSM). More importantly, this pre-solution process targets the age-strengthening characteristics of titanium bronze alloys, controlling the degree of supersaturated solid solution formation, providing a core material basis suitable for the Ti-based precipitates of titanium bronze for subsequent aging treatment. This application can obtain a stable supersaturated solid solution state simply through solution water quenching, meeting the process requirements for crack repair. Subsequently, friction stir processing is performed along the crack path. In this application, the friction stir processing directly targets the crack path, and the core... The process utilizes solid-state processing below the alloy's melting point to achieve in-situ metallurgical bonding at the crack interface, compaction to eliminate internal voids, and dynamic recrystallization to form a refined microstructure. This not only eliminates weld defects but also achieves closed-loop repair of crack defects, rather than simply connecting components. It achieves microstructural densification and grain refinement without the need for additional rapid cooling steps, meeting the core requirements of titanium bronze crack repair. Finally, the alloy repaired by friction stir processing is heated to 400–500°C, held for 6–8 hours, and then water-cooled for age strengthening. Leveraging the supersaturated solid solution matrix formed in the initial solid solution treatment and the grains refined by friction stir processing, it promotes the uniform precipitation of nanoscale coherent Ti-based strengthening phases within the matrix. This compensates for the matrix softening caused by partial dissolution of the precipitated phases during friction stir processing, achieving a synergistic effect of grain refinement and precipitation strengthening, restoring the performance of the repaired area to the level of the base material. The entire process is simple, with controllable parameters, requiring no specialized equipment, effectively extending the service life of titanium bronze alloy components and overcoming the inherent defects of traditional repair processes. Attached Figure Description

[0017] Figure 1 This is a microstructure diagram of the repaired titanium bronze alloy crack in Comparative Example 1 of the present invention; Figure 2 This is a microstructure diagram of the repaired titanium bronze alloy crack in Example 1 of the present invention; Figure 3 The tensile property curves of the repaired titanium bronze alloys in Comparative Example 1 and Example 1 of this invention are shown under different parameters. Detailed Implementation

[0018] The present invention will be further described clearly and in detail below with reference to specific embodiments and the accompanying drawings. Those skilled in the art will be able to implement the present invention based on these descriptions. Furthermore, the embodiments of the present invention described below are generally only some, not all, of the embodiments of the present invention. Therefore, all other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0019] To address the problems of surface cracking in titanium bronze alloys under high temperature, load, and corrosive environments, and the tendency of traditional fusion welding repair to result in grain coarsening, precipitate degradation, large thermal stress and deformation, and low performance in the repaired area, this invention first heat-treats the pre-repair area to improve its processing plasticity, then uses friction stir processing to achieve in-situ closure and microstructure densification of the pre-repair area, and finally achieves nano-precipitate regeneration and strengthening through matched aging treatment. The repaired area obtains a uniform ultrafine-grained structure, and the synergistic effect of grain refinement and precipitation strengthening restores its hardness, strength, and other properties to the level of the base material. This method is process-controllable, has low heat input, no molten pool defects, and is environmentally friendly and efficient. It is suitable for repairing cracks and surface damage in key components such as large-size titanium bronze elastic elements, connectors, molds, crystallizer liners, and wear-resistant structural parts, and has extremely high engineering application and remanufacturing value.

[0020] Specifically, the present invention provides a method for repairing cracks in titanium bronze alloys based on the synergistic effect of friction stir processing and aging, comprising the following steps: Step 1: Pre-treatment of the base material: Take a titanium bronze alloy plate with cracks, and perform surface cleaning, degreasing, and rust removal on the area to be repaired to ensure a clean surface and expose the titanium bronze alloy substrate. The titanium bronze alloy material can be Cu-Ti alloy, Cu-Ti-Fe alloy, or Cu-Ti-Cr alloy. By mass percentage, the Cu-Ti alloy contains 1.0%~4.0% Ti, with the balance being Cu; the Cu-Ti-Fe alloy contains 1.0%~4.0% Ti, 0.15%~0.25% Fe, with the balance being Cu; and the Cu-Ti-Cr alloy contains 1.0%~4.0% Ti, 0.15%~0.25% Cr, with the balance being Cu.

[0021] Step Two: Heat Treatment of the Repair Area: The titanium bronze plate to be repaired, pretreated in Step One, undergoes solution heat treatment. At high temperature, the precipitated phases dissolve, atoms diffuse fully, composition is homogenized, and internal stress is released, thereby improving the workability of the repair area and facilitating subsequent processing and repair. During solution heat treatment, the titanium bronze alloy to be repaired is heated to 800~900℃ and held for 0.5~2 hours, followed by water quenching.

[0022] Step 3: Friction Stir Processing Repair: Fix the titanium bronze alloy plate to be repaired, which underwent solution heat treatment in Step 2, onto the substrate. Then, select a suitable stirring head to perform friction stir processing repair on the hot titanium bronze alloy plate in the area to be repaired. During friction stir processing repair, the stirring needle travels along the crack path. By utilizing frictional heat and intense plastic deformation, the crack interface is metallurgically bonded in situ, the voids are compacted, and dynamic recrystallization is performed to form ultrafine equiaxed crystals, thereby eliminating defects and increasing density.

[0023] In the above process, a frustum-shaped tungsten-rhenium alloy stirring head is used. The stirring head is made of tungsten-rhenium alloy to meet the processing requirements of titanium bronze alloy. The diameter of the stirring head is 3~6 mm, the diameter of the stirring head shoulder is 12~20 mm, and the diameter of the stirring pin is 1.5~3 mm. The pin length must match the depth of the repair area, and the pin length is not less than the depth of the repair area. When performing friction stir welding on titanium bronze alloy plates, the stirring head rotation speed is 600~1200 r / min, the travel speed is 60~100 mm / min, the tilt angle of the stirring head is 2°±0.5°, and the reduction is 0.3~0.5 mm. The tilt angle of the stirring head refers to the angle between the axis of the stirring head and the perpendicular line of the substrate.

[0024] Step Four: Aging Strengthening Treatment: The plate material repaired through the friction stir processing in Step Three undergoes aging heat treatment to further restore the performance of the repaired area. The aging heat treatment temperature is 350℃~450℃, and the holding time is 6~8 hours, followed by water cooling to complete the aging strengthening treatment. Aging treatment promotes the precipitation of nanoscale coherent strengthening phases in the matrix, compensating for the softening caused by FSP through ororovan strengthening, achieving a synergistic effect of ultrafine grain strengthening and precipitation strengthening.

[0025] The repair method of the present invention is based on the synergistic repair of titanium bronze alloy cracks through pre-repair heat treatment, friction stirring, and aging, which can achieve efficient crack repair and near-material-level performance restoration. In the above parameters, the value after the "±" sign is the deviation of the corresponding parameter in the actual execution process, and the value before the "±" sign is the set value of the corresponding parameter in the actual execution process.

[0026] Comparative Example 1 This comparative example serves as a control treatment example for the base material. The specific process flow is as follows: Step 1: Pre-treatment of the base material: Take a 3mm thick titanium bronze alloy plate (normal plate, the difference from Example 1 is that the material has no cracks or defects), and perform surface cleaning, degreasing, and rust removal treatment to make the surface of the titanium bronze alloy plate clean and expose the titanium bronze alloy plate substrate. The titanium bronze plate used in this comparative example has a composition of Cu-3.2Ti (i.e., by mass percentage, the Ti content in the Cu-Ti alloy is 3.2%, and the balance is Cu).

[0027] Step 2: Solution heat treatment: The titanium bronze plate pretreated in Step 1 is subjected to solution heat treatment. During solution heat treatment, the titanium bronze alloy is heated to 850℃ and held for 1.5 h, followed by water quenching.

[0028] Step 3: Aging strengthening treatment: The titanium bronze sheet that has undergone solution heat treatment in Step 2 is subjected to aging heat treatment at a temperature of 400 ℃ and a holding time of 8 h, followed by water cooling to complete the aging strengthening treatment.

[0029] The microstructure of the plate at the crack after the comparative treatment is shown in the figure below. Figure 1 As shown, the material microstructure consists of uniform equiaxed grains with an average grain size of 36.7 μm and relatively uniform orientation.

[0030] See Figure 3 The board treated in this comparative example has a tensile strength of 472.4 MPa, which is the tensile strength of the parent material, and an elongation of 35.6%.

[0031] Example 1 The specific process flow of the titanium bronze alloy crack repair method based on the synergistic effect of friction stir processing and aging in this embodiment is as follows: Step 1: Pre-treatment of the base material: Take a 3mm thick titanium bronze alloy sheet and clean, degrease, and remove rust from the area to be repaired to ensure the surface of the titanium bronze alloy sheet is clean and exposes the titanium bronze alloy substrate. In this embodiment, the titanium bronze sheet used has a composition of Cu-3.2Ti (i.e., by mass percentage, the Cu-Ti alloy contains 3.2% Ti and the balance is Cu).

[0032] Step 2: Solution heat treatment of the repair area: The titanium bronze plate to be repaired, which has been pretreated in Step 1, is subjected to solution heat treatment. During solution heat treatment, the titanium bronze alloy to be repaired is heated to 850℃ and held for 1.5 h, followed by water quenching.

[0033] Step 3: Friction Stir Processing Repair: Fix the titanium bronze alloy plate to be repaired, which has undergone solution heat treatment in Step 2, onto the substrate. Then, use a frustum-shaped tungsten-rhenium alloy stirring head to perform friction stir processing repair on the hot titanium bronze alloy plate in the area to be repaired until the surface morphology is good.

[0034] The stirring head has a shoulder diameter of 12 mm, a stirring pin diameter of 2.5 mm, and a pin length of 3 mm. When performing friction stir welding on titanium bronze alloy plates, the stirring head rotates at 800 r / min, the processing speed is 80 mm / min, the tilt angle of the stirring head is 2°±0.5°, and the reduction is 0.3 mm.

[0035] Step 4: Aging strengthening treatment: The board material repaired by stirring and friction processing in step 3 is subjected to aging heat treatment at a temperature of 400 ℃ and a holding time of 8 h, followed by water cooling to complete the aging strengthening treatment.

[0036] The microstructure of the board material repaired according to this embodiment at the crack is shown in the image below. Figure 2 As shown, the grain size at the repair site is refined to 3~6 μm, exhibiting a good equiaxed fine-grained structure.

[0037] See Figure 3 The board material repaired in this embodiment has a tensile strength of 431.3 MPa, reaching 91.3% of the tensile strength of the parent material, and its performance has been restored to the level of the parent material after repair; the elongation is 22.5%, reaching 63.2% of the elongation of the parent material, and the repair effect is significant.

[0038] Example 2 The process is the same as in Example 1, except that in step three, the stirring head speed is 600 r / min.

[0039] See Figure 3 The board material repaired in this embodiment has a tensile strength of 473.0 MPa, reaching 100.1% of the tensile strength of the parent material, and its performance has been restored to the level of the parent material after repair; the elongation rate is 11.3%, reaching 31.7% of the elongation rate of the parent material, and the repair effect is significant.

[0040] Example 3 The process is the same as in Example 1, except that in step three, the stirring head speed is 1000 r / min.

[0041] See Figure 3 The board material repaired in this embodiment has a tensile strength of 356.2 MPa, reaching 77.3% of the tensile strength of the parent material, and its performance has been restored to the level of the parent material after repair; the elongation rate is 17.5%, reaching 49.2% of the elongation rate of the parent material, and the repair effect is significant.

[0042] Example 4 The process is the same as in Example 1, except that in step three, the stirring head speed is 1200 r / min.

[0043] See Figure 3 The board material repaired in this embodiment has a tensile strength of 366.5 MPa, reaching 77.6% of the tensile strength of the parent material, and its performance has been restored to the level of the parent material after repair; the elongation is 16.9%, reaching 47.5% of the elongation of the parent material, and the repair effect is significant.

[0044] like Figure 3As shown in the results from Comparative Examples 1 to 4, the ultimate tensile strength and elongation of the base material (BM) treated in Comparative Example 1 were 472.4 MPa and 35.6%, respectively. Comparing different rotational speeds, the tensile strengths at 600 rpm, 800 rpm, 1000 rpm, and 1200 rpm were 473.0 MPa, 431.3 MPa, 356.2 MPa, and 366.5 MPa, respectively. The tensile strength decreased with increasing rotational speed, while the elongation was 11.3%, 22.5%, 17.5%, and 16.9%, respectively. The elongation was lower at lower rotational speeds, and increasing the rotational speed could improve the elongation to some extent. Considering both tensile strength and elongation, the joint with the best tensile performance under the welding parameters of 800 rpm had the ultimate tensile strength and elongation of 431.3 MPa and 22.5%, respectively 91.3% and 63.2% of the base material. Within the selected repair parameter range, the tensile strength after repair reaches 77% to 100.1% of the parent material, and the performance after repair reaches approximately the level of the parent material, indicating a good repair effect.

[0045] Example 5 The specific process flow of the titanium bronze alloy crack repair method based on the synergistic effect of friction stir processing and aging in this embodiment is as follows: Step 1: Pre-treatment of the base material: Take a 3mm thick titanium bronze alloy sheet and clean, degrease, and remove rust from the area to be repaired to ensure the surface of the titanium bronze alloy sheet is clean and exposes the titanium bronze alloy substrate. In this embodiment, the titanium bronze sheet used has a composition of Cu-3.2Ti-0.2Fe (i.e., by mass percentage, the Cu-3.2Ti-0.2Fe alloy contains 3.2% Ti, 0.2% Fe, and the balance is Cu).

[0046] Step 2: Solution heat treatment of the repair area: The titanium bronze plate to be repaired, which has been pretreated in Step 1, is subjected to solution heat treatment. During solution heat treatment, the titanium bronze alloy to be repaired is heated to 830℃ and held for 2.0 h, followed by water quenching.

[0047] Step 3: Friction Stir Processing Repair: Fix the titanium bronze alloy plate to be repaired, which has undergone solution heat treatment in Step 2, onto the substrate. Then, use a frustum-shaped tungsten-rhenium alloy stirring head to perform friction stir processing repair on the hot titanium bronze alloy plate in the area to be repaired until the surface morphology is good.

[0048] The stirring head is made of tungsten-rhenium alloy, with a shoulder diameter of 12 mm, a stirring pin diameter of 2.5 mm, and a pin length of 3 mm. When performing friction stir welding on titanium bronze alloy plates, the stirring head rotates at 800 r / min, the processing speed is 100 mm / min, the tilt angle of the stirring head is 2°±0.5°, and the reduction is 0.4 mm.

[0049] Step 4: Aging strengthening treatment: The board material repaired by stirring and friction processing in step 3 is subjected to aging heat treatment at a temperature of 350 ℃ and a holding time of 7 h, followed by water cooling to complete the aging strengthening treatment.

[0050] The tensile strength of the board after repair in this embodiment is 472 MPa, reaching 87% of the tensile strength of the parent material. The performance after repair is restored to the level of the parent material, and the repair effect is significant.

[0051] Example 6 The specific process flow of the titanium bronze alloy crack repair method based on the synergistic effect of friction stir processing and aging in this embodiment is as follows: Step 1: Pre-treatment of the base material: Take a 3mm thick titanium bronze alloy sheet and clean, degrease, and remove rust from the area to be repaired to ensure the surface of the titanium bronze alloy sheet is clean and exposes the titanium bronze alloy substrate. In this embodiment, the titanium bronze sheet used has a composition of Cu-3.2Ti-0.2Cr (i.e., by mass percentage, the Cu-3.2Ti-0.2Fe alloy contains 3.2% Ti, 0.2% Cr, and the balance is Cu).

[0052] Step 2: Solution heat treatment of the repair area: The titanium bronze plate to be repaired, which has been pretreated in Step 1, is subjected to solution heat treatment. During solution heat treatment, the titanium bronze alloy to be repaired is heated to 880℃ and held for 0.5 h, followed by water quenching.

[0053] Step 3: Friction Stir Processing Repair: Fix the titanium bronze alloy plate to be repaired, which has undergone solution heat treatment in Step 2, onto the substrate. Then, use a frustum-shaped tungsten-rhenium alloy stirring head to perform friction stir processing repair on the hot titanium bronze alloy plate in the area to be repaired until the surface morphology is good.

[0054] The stirring head is made of tungsten-rhenium alloy, with a shoulder diameter of 12 mm, a stirring pin diameter of 2.5 mm, and a pin length of 3 mm. When performing friction stir welding on titanium bronze alloy plates, the stirring head rotates at 1100 r / min, the processing speed is 60 mm / min, the tilt angle of the stirring head is 2°±0.5°, and the reduction is 0.5 mm.

[0055] Step 4: Aging strengthening treatment: The board material repaired by stirring and friction processing in step 3 is subjected to aging heat treatment at a temperature of 450 ℃ and a holding time of 6 h, followed by water cooling to complete the aging strengthening treatment.

[0056] The tensile strength of the board after repair in this embodiment is 429 MPa, which is 83% of the tensile strength of the parent material. The performance after repair is restored to the level of the parent material, and the repair effect is significant.

[0057] The experimental results above show that the technical solution of the present invention has the following characteristics: 1) Solid-state repair eliminates the defects of melting repair, significantly improving the dimensional accuracy and structural integrity of components. This invention employs a solid-state repair method using friction stir processing, with the processing temperature consistently below the melting point of titanium bronze alloy. This fundamentally avoids fatal defects such as hot cracks and inclusions that can occur during melting repair. Simultaneously, the low heat input effectively controls the range of the heat-affected zone, preventing problems such as grain coarsening and uneven microstructure within the heat-affected zone.

[0058] 2) The repaired area has a dense and uniform structure with a significant effect of ultra-fine grains. Through the intense plastic deformation and dynamic recrystallization during the FSP process, the crack area achieves in-situ metallurgical bonding. The originally loose crack interface is compacted and dense, without any defects such as pores or gaps. The repaired area forms an ultra-fine equiaxed grain structure with an average size of 3~6 μm. Compared with the coarse grains of the parent material, the grain size is greatly refined, which not only improves the strength and toughness of the repaired area, but also improves its stress relaxation resistance and heat resistance stability.

[0059] 3) Performance is fully restored and stabilized, reaching the level of the base material, thus extending the service life of the component. This invention achieves a dual strengthening effect of "grain refinement strengthening and nano-precipitation strengthening" through the synergistic effect of FSP and aging treatment. FSP achieves ultra-fine grains, while aging treatment promotes the precipitation of nanoscale coherent Ti-based strengthening phases in the matrix, effectively compensating for the softening problem in the repair area caused by the dissolution of Ti-based precipitates during FSP. This allows damaged components to be put back into service, significantly extending their service life and reducing component replacement costs.

[0060] 4) The process is highly controllable and stable, facilitating industrial application. This invention clearly defines the range of key process parameters for FSP, such as rotational speed, travel speed, indentation, and tilt angle, as well as the control parameters for aging treatment, such as temperature and time. The process window is clear, and process parameters can be adjusted according to specific circumstances to ensure the stability and consistency of the repair effect. Furthermore, the friction stir processing equipment and aging treatment equipment used are all conventional industrial equipment, requiring no special customization. The equipment investment cost is low, and the operating threshold is not high, making it easy to promote and apply in various manufacturing and remanufacturing enterprises, and possessing broad prospects for industrial application.

[0061] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A method for repairing cracks in a titanium bronze alloy based on synergistic friction stir processing and aging, characterized by, The process includes the following: The titanium bronze alloy with cracks to be repaired is subjected to solution heat treatment. During solution heat treatment, the titanium bronze alloy to be repaired is heated to 800~900℃ and held for 0.5~2 h, followed by water quenching. Friction stir repair was performed on titanium bronze alloys that had undergone solution heat treatment. During the friction stir repair, the stirring pin traveled along the crack path. Aging strengthening treatment was performed on titanium bronze alloys that had undergone friction stir processing to repair cracks in the titanium bronze alloys. During the aging strengthening treatment, the titanium bronze alloys that had undergone friction stir processing were heated to 400~500℃ and held at that temperature for 6~8 hours, followed by water cooling to complete the aging strengthening treatment.

2. The method for repairing cracks in a titanium bronze alloy based on friction stir processing and aging synergy according to claim 1, characterized in that, When performing friction stir repair, a tungsten-rhenium alloy stirring head is used.

3. The method for repairing cracks in titanium bronze alloy based on friction stir processing and aging synergy according to claim 1, characterized in that, When performing friction stir repair, the diameter of the stirring head is 3~6 mm, the diameter of the shoulder is 12~20 mm, and the length of the stirring pin is matched with the crack depth.

4. The method for repairing cracks in titanium bronze alloys based on the synergistic effect of friction stir processing and aging, as described in claim 3, is characterized in that... The diameter of the stirring needle is 1.5~3.0 mm.

5. The method for repairing cracks in titanium bronze alloys based on the synergistic effect of friction stir processing and aging, as described in claim 1, is characterized in that... When performing friction stir repair, the stirring pin rotates at 600~1200 r / min, travels at 60~100 mm / min, presses down at 0.3~0.5 mm, and tilts at 2°~3°.

6. The method for repairing cracks in titanium bronze alloys based on the synergistic effect of friction stir processing and aging, as described in claim 1, is characterized in that... It also includes the process of pre-treating the cracked titanium bronze alloy to be repaired, including: cleaning, degreasing and derusting the cracked area.

7. The method for repairing cracks in titanium bronze alloys based on the synergistic effect of friction stir processing and aging, as described in claim 1, is characterized in that... The titanium bronze alloy is made of Cu-Ti alloy, Cu-Ti-Fe alloy, or Cu-Ti-Cr alloy.

8. The method for repairing cracks in titanium bronze alloys based on the synergistic effect of friction stir processing and aging, as described in claim 7, is characterized in that... In the Cu-Ti alloy, the Ti content is 1.0% to 4.0% by mass, and the balance is Cu.

9. A method for repairing cracks in titanium bronze alloys based on the synergistic effect of friction stir processing and aging, as described in claim 7, is characterized in that... In the Cu-Ti-Fe alloy, the Ti content is 1.0%~4.0% by mass, the Fe content is 0.15%-0.25%, and the balance is Cu.

10. A method for repairing cracks in titanium bronze alloys based on the synergistic effect of friction stir processing and aging, as described in claim 7, is characterized in that... In the Cu-Ti-Cr alloy, the Ti content is 1.0%~4.0% by mass, the Cr content is 0.15%-0.25%, and the balance is Cu.

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