A method and system for composite preparation of a high-temperature / high-strength dual-titanium alloy gradient structure

Abstract

A method and system for composite preparation of a high-temperature / high-strength dual titanium alloy gradient structure, belonging to the field of metal component manufacturing and forming; the method steps are as follows: forging the blank to initially obtain the shape dimensions and different tissue morphologies required for the two alloy blanks; performing solution treatment on the high-temperature titanium alloy, and then machining the two blanks into pre-welding blanks; fixing the two titanium alloy blanks on an inertia friction welding device, respectively serving as the rotating end and the advancing end of the inertia friction welding, and performing inertia friction welding according to the set process to obtain a high-temperature / high-strength dual titanium alloy blank; then performing solution treatment on the dual titanium alloy blank, cooling to room temperature, and then performing aging treatment at a temperature of 550°C to 750°C for 2h to 8h to obtain a high-temperature / high-strength dual titanium alloy gradient structure. The present invention combines processes such as forging, heat treatment, and inertia friction welding to achieve the gradient tissue distribution of different parts of the high-temperature / high-strength dual titanium alloy component and achieve the gradient performance target for key components of the engine.

Description

Technical Field

[0001] The present invention belongs to the field of manufacturing and forming of metal components, and particularly relates to a method and system for composite preparation of a high-temperature / high-strength dual-titanium alloy gradient structure. Background Art

[0002] With the continuous improvement of the comprehensive performance of aircraft, the thrust-to-weight ratio of engines is getting higher and higher, and the requirements for the service temperature and performance of internal metal components are also becoming more and more stringent. Different parts of the same component need to meet large temperature gradients and stress gradients. However, existing high-temperature titanium alloys and high-strength titanium alloys have single performance and can only be used within specific temperature and specific stress ranges, and cannot meet the performance requirements of both high temperature and high strength at the same time, and cannot achieve the service goals of high temperature gradients and high stress gradients in different parts of key components. Connecting two titanium alloy materials with different properties to prepare a dual-titanium alloy component can meet this requirement of high temperature gradient and high performance gradient, but the bonding performance of the two alloys is crucial. Fusion welding and pressure welding are common preparation processes for connecting different titanium alloy materials and are often used to prepare dual-alloy components. However, due to the large difference in performance requirements for different parts of the dual-alloy key components for engines, for the dual-alloy components prepared simply by fusion welding and pressure welding, the microstructure and performance of the joint part are often quite different from those of the two alloy matrix materials, resulting in "weak connection" or "high-strength" connection at the joint part, and the performance of different parts cannot be balanced and matched, and the required gradient performance goal cannot be achieved. Therefore, how to control the microstructure morphology of different parts of the dual-titanium alloy component to achieve gradient performance is crucial.

[0003] Avoiding the formation of "weak connection" or "high-strength" joints between the two titanium alloys and achieving high-quality bonding of the two titanium alloys through the preparation process, so that the performance of the connection part and the connecting alloy reaches a gradient transition effect, is a difficult problem faced by the preparation of dual-titanium alloy components and is also an urgent need for current key engine equipment. Although the connection of two titanium alloys can be achieved through the welding process, how to achieve gradient performance through the regulation of the gradient microstructure morphology of different parts is crucial. Although the existing welding process can achieve the purpose of different compositions with different service performances by connecting two different titanium alloys, it does not utilize the effect that different microstructures of titanium alloys have different service performances, and cannot fully achieve the best performance matching of the two titanium alloys.

[0004] In order to achieve the gradient properties of dual titanium alloy components, the present invention proposes a method for composite preparation of a high-temperature / high-strength dual titanium alloy gradient structure. According to the service performance requirements of the dual alloy components, two titanium alloy materials with different performance advantages, namely high-temperature titanium alloy and high-strength titanium alloy, are selected for forging and single heat treatment to obtain different microstructural morphologies. Then, the two alloys are joined by inertia friction welding process. Finally, multiple heat treatments are carried out according to the gradient performance distribution to achieve the gradient structure distribution of the joint and the two matrix titanium alloys, and the gradient service performance of the high-temperature / high-strength dual alloy components is obtained. Summary of the Invention

[0005] Technical problems to be solved:

[0006] To avoid the deficiencies of the prior art and solve the problem of gradient performance distribution of dual titanium alloy components, the present invention proposes a method for composite preparation of a high-temperature / high-strength dual titanium alloy gradient structure. According to the service performance requirements of key components of the engine, the blank forging is carried out by combining the performance advantages of high-temperature and high-strength titanium alloy materials, and then single heat treatment is carried out to preliminarily regulate the microstructural morphology. Then, inertia friction welding is used to connect the two titanium alloys, and finally multiple heat treatments are carried out to regulate the structure of the joint part and the two alloy matrices to be gradient distributed.

[0007] The technical solution of the present invention is: a method for composite preparation of a high-temperature / high-strength dual titanium alloy gradient structure, which is characterized in that the specific steps are as follows:

[0008] Step 1: Blank forging: According to the corresponding relationship between the microstructures and mechanical properties of high-temperature and high-strength titanium alloys, forging is carried out to initially obtain the shape dimensions and different microstructural morphologies required for the two alloy blanks;

[0009] Step 2: Single heat treatment: At a temperature of the phase transformation temperature T of the high-temperature titanium alloy β -(30 - 50°C), solution treatment of the high-temperature titanium alloy is carried out for 1h - 4h; the high-strength titanium alloy is not heat-treated; then the two blanks are machined into pre-welding blanks;

[0010] Step 3: Inertia friction welding: Fix the two titanium alloy blanks prepared in Step 2 on the inertia friction welding equipment, and use them as the rotating end and the advancing end of the inertia friction welding respectively. Inertia friction welding is carried out according to the set process to obtain a high-temperature / high-strength dual titanium alloy blank;

[0011] Step 4: Multiple heat treatments: At a temperature of the phase transformation temperature T of the high-strength titanium alloy β -(30 - 50°C), solution treatment of the dual titanium alloy blank obtained in Step 3 is first carried out for 1h - 4h, cooled to room temperature, and then aging treatment is carried out at a temperature of 550°C - 750°C for 2h - 8h to obtain a high-temperature / high-strength dual titanium alloy gradient structure.

[0012] A further technical solution of the present invention is that in step 1, heating is performed at a temperature of the high-strength titanium alloy phase transformation temperature T β +(10 - 30°C) and forging deformation with a deformation amount of 40% - 60% is carried out. Heating is performed at a temperature of the high-temperature titanium alloy T β -(30 - 50°C) and forging deformation with a deformation amount of ≥50% is carried out.

[0013] A further technical solution of the present invention is that in step 2, after solution treatment of the high-temperature titanium alloy, it is cooled to room temperature by oil cooling or air cooling.

[0014] A further technical solution of the present invention is that in step 3, inertia friction welding is carried out on the two billets at a rotational speed of 200 revolutions per minute to 750 revolutions per minute, and the upsetting pressure is maintained for 10 s to 40 s after welding.

[0015] A further technical solution of the present invention is that in step 4, it is cooled to room temperature by oil cooling or air cooling.

[0016] A high-temperature / high-strength dual-titanium alloy gradient structure composite preparation system, characterized in that it includes a blank forging module, a heat treatment module, and an inertia friction welding module;

[0017] The blank is heated and forged through the blank forging module;

[0018] The high-temperature titanium alloy forged in step 1 is subjected to solution treatment through the heat treatment module, and the dual-titanium alloy blank obtained in step 3 is subjected to solution treatment;

[0019] The two titanium alloy billets prepared in step 2 are subjected to inertia friction welding through the inertia friction welding module.

[0020] Beneficial effects

[0021] The beneficial effects of the present invention are as follows: The method of the present invention combines processes such as forging, heat treatment, and inertia friction welding, and realizes the gradient structure distribution of different parts of the high-temperature / high-strength dual-titanium alloy component through the regulation of the microstructure morphology under different process actions, so as to achieve the gradient performance target for key components of the engine.

[0022] Compared with other preparation methods of dual titanium alloy components, in step 1 of this method, forging deformation is carried out above the phase transformation temperature of high-strength titanium alloy and below the phase transformation point of high-temperature titanium alloy. Different microstructure morphologies such as basket weave, equiaxed, and duplex can be obtained according to performance requirements, meeting the performance requirements of the two matrix material parts of the dual titanium alloy components, providing an internal driving force for the microstructure morphology control of the heat treatment in subsequent steps 2 and 4, and providing a necessary blank shape for step 3 inertia friction welding. In step 2, only the high-temperature titanium alloy is subjected to single solution treatment at a relatively high temperature, while the high-strength titanium alloy is not heat-treated. This is mainly considered in coordination with the heat treatment in subsequent weld step 4. The heat treatment temperature of the high-temperature titanium alloy is high, and the heat treatment temperature of the high-strength titanium alloy is low. The setting of relatively high temperature parameters and reasonable solution time can fully improve the performance of the high-temperature titanium alloy, avoiding the situation that the performance of the high-temperature titanium alloy cannot be fully improved due to the low heat treatment temperature in step 4. Without heat treatment of the high-strength titanium alloy, it can avoid the repeated heat treatment of the high-strength titanium alloy caused by step 4 heat treatment, which affects the performance, and provides conditions for improving the performance of the weld after step 3. In step 3, inertia friction welding can connect the two blanks obtained in the previous steps to prepare a dual alloy blank part. By reasonably controlling the rotational speed, it can ensure better energy input of inertia friction welding, realize high-reliability connection of the two alloys and control the microstructure morphology of the connection part, providing a necessary process means for obtaining the best shape size and tissue performance of the dual alloy component. In step 4, solution treatment is carried out on the dual alloy blank part. The setting of relatively low solution temperature parameters and reasonable solution time can not only ensure that the high-strength titanium alloy that has not been solution-treated in step 2 obtains the driving force for microstructure transformation, but also change the microstructure morphology of the connection part in step 3 inertia friction welding. Combined with the setting of aging temperature and aging time according to the service temperature of the titanium alloy, the precipitation phases in different parts of the dual alloy blank part can be fully precipitated, and finally the gradient tissue control is completed, achieving the effect of gradient performance control from both the alloy composition and microstructure morphology of the two alloys.

[0023] This method realizes the gradient tissue control of high-temperature / high-strength dual titanium alloy through different process combinations, expands the manufacturing mode of obtaining single performance by traditional single preparation process, and has practical application value in the field of forming manufacturing of dual titanium alloy components. Brief Description of the Drawings

[0024] Figure 1 It is a schematic diagram of a preparation method of inertia friction welding for obtaining the gradient tissue of dual titanium alloy;

[0025] Figure 2 Microstructures of IMI834 high-temperature titanium alloy and Ti6246 high-strength titanium alloy after forging;

[0026] Figure 3 Machining pictures of IMI834 high-temperature titanium alloy and Ti6246 high-strength titanium alloy;

[0027] Figure 4Gradient microstructure of different parts of IMI834 high-temperature / Ti6246 high-strength dual-titanium alloy;

[0028] Figure 5 Microstructure of IMI834 high-temperature titanium alloy and Ti6246 high-strength titanium alloy after forging;

[0029] Figure 6 Machining pictures of IMI834 high-temperature titanium alloy and Ti6246 high-strength titanium alloy;

[0030] Figure 7 Gradient microstructure of different parts of IMI834 high-temperature / Ti6246 high-strength dual-titanium alloy. Detailed implementation manners

[0031] The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0032] In this embodiment, an inertia friction welding preparation method for obtaining a gradient microstructure of a dual-titanium alloy is provided, and the specific steps are as follows:

[0033] Step 1: Blank forging: According to the corresponding relationship between the microstructure and mechanical properties of the high-temperature and high-strength titanium alloys, the high-strength titanium alloy is heated at a temperature of T β +(10 - 30°C) and forged with a deformation amount of 40% - 60%, and the high-temperature titanium alloy is heated at a temperature of T β -(30 - 50°C) and forged with a deformation amount of ≥50%( Figure 1 (a)), initially obtaining the required shape dimensions and different tissue morphologies of the two alloy blanks.

[0034] Step 2: Single heat treatment: At a temperature of T β -(30 - 50°C) of the high-temperature titanium alloy, the high-temperature titanium alloy is solution-treated for 2h - 4h( Figure 1 (b)), and after the solution treatment, it is cooled to room temperature by oil cooling or air cooling. The high-strength titanium alloy is not heat-treated, and then the two blanks are machined into pre-welding bodies.

[0035] Step 3: Inertia friction welding: Fix the two titanium alloy pre-welding bodies prepared in Step 2 on the inertia friction welding equipment, and use them as the rotating end and the advancing end of the inertia friction welding respectively. The two pre-welding bodies are subjected to inertia friction welding at a rotational speed of 200 rpm - 750 rpm, and after welding, upset forging is carried out and pressure is maintained for 10s - 40s to obtain a high-temperature / high-strength dual-titanium alloy blank( Figure 1 (c)).

[0036] Step 4: Multiple heat treatments: At the phase transformation temperature T β-(30 to 50 °C), the double titanium alloy blank in step 3 is first solution-treated for 2 h to 4 h, cooled to room temperature by oil cooling or air cooling, and then aged at 550 °C to 750 °C for 4 h to 8 h ( Figure 1 (d)), obtaining a high-temperature / high-strength double titanium alloy gradient structure.

[0037] Example 1:

[0038] An inertia friction welding preparation method for obtaining a double titanium alloy gradient structure, the specific steps are as follows:

[0039] Step 1: Select IMI834 high-temperature titanium alloy and Ti6246 high-strength titanium alloy as objects, heat at a temperature of Ti6246 high-strength titanium alloy phase transformation temperature T β +10 °C and perform forging deformation with a 50% deformation amount, heat at a temperature of IMI834 high-temperature titanium alloy T β -50 °C and perform forging deformation with a 50% deformation amount to initially obtain the shape dimensions and different tissue morphologies required for the two alloy blanks ( Figure 2 ).

[0040] Step 2: At a temperature of IMI834 high-temperature titanium alloy phase transformation temperature T β -30 °C, the high-temperature titanium alloy is solution-treated for 2 h, and after solution treatment, it is cooled to room temperature by oil cooling. The Ti6246 high-strength titanium alloy is not heat-treated, and then the two blanks are machined into pre-welded bodies ( Figure 3 ).

[0041] Step 3: Fix the two titanium alloy blanks prepared in step 2 on an inertia friction welding device, respectively as the rotating end and the advancing end of inertia friction welding, and perform inertia friction welding on the two blanks at a rotational speed of 600 revolutions per minute. After welding, upset and hold pressure for 20 s to obtain a high-temperature / high-strength double titanium alloy blank.

[0042] Step 4: At a temperature of Ti6246 high-strength titanium alloy phase transformation temperature T β -30 °C, the double titanium alloy blank in step 3 is first solution-treated for 2 h, cooled to room temperature by air cooling, and then aged at 600 °C for 8 h to obtain an IMI834 high-temperature / Ti6246 high-strength double titanium alloy gradient structure ( Figure 4 ).

[0043] Example 2:

[0044] An inertia friction welding preparation method for obtaining a double titanium alloy gradient structure, the specific steps are as follows:

[0045] Step 1: Select IMI834 high-temperature titanium alloy and Ti6246 high-strength titanium alloy as objects. Heat them at a temperature of T + 30°C for the Ti6246 high-strength titanium alloy and perform forging deformation with a 50% deformation amount. Heat them at a temperature of T - 30°C for the IMI834 high-temperature titanium alloy and perform forging deformation with a 50% deformation amount to initially obtain the shape dimensions and different microstructures required for the two alloy blanks ( β ). β ). Figure 5 )

[0046] Step 2: At a temperature of T - 30 for the IMI834 high-temperature titanium alloy, perform a solution treatment on the high-temperature titanium alloy for 2 hours. After the solution treatment, cool it to room temperature by oil quenching. The Ti6246 high-strength titanium alloy does not undergo heat treatment. Then, machine the two blanks into pre-weld blanks ( β ). Figure 6 )

[0047] Step 3: Fix the two titanium alloy blanks prepared in Step 2 on an inertia friction welding device, and use them as the rotating end and the advancing end of inertia friction welding respectively. Perform inertia friction welding on the two blanks at a rotational speed of 700 revolutions per minute. After welding, perform upset forging and hold the pressure for 20 s to obtain a high-temperature / high-strength dual-titanium alloy blank.

[0048] Step 4: At a temperature of T - 30°C for the Ti6246 high-strength titanium alloy, first perform a solution treatment on the dual-titanium alloy blank in Step 3 for 2 hours, cool it to room temperature by air cooling, and then perform an aging treatment at a temperature of 650°C for 8 hours to obtain an IMI834 high-temperature / Ti6246 high-strength dual-titanium alloy gradient structure ( β ). Figure 7 )

[0049] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention without departing from the principles and purposes of the present invention.

Claims

1. A method for composite preparation of a high-temperature / high-strength dual-titanium alloy gradient structure, characterized in that The specific steps are as follows: Step 1: Blank forging: According to the corresponding relationship between the microstructures and mechanical properties of two kinds of titanium alloys with high temperature and high strength, forging is carried out to initially obtain the shape dimensions and different tissue forms required for the two alloy blanks; the two kinds of titanium alloys with high temperature and high strength are IMI834 high-temperature titanium alloy and Ti6246 high-strength titanium alloy; Heat at a temperature of the phase transition temperature T of the high-strength titanium alloy + (10 - 30 °C) and perform forging deformation with a deformation amount of 40% - 60%. Heat at a temperature of the high-temperature titanium alloy T β - (30 - 50 °C) and perform forging deformation with a deformation amount of ≥ 50%; β ​ Step 2: Single heat treatment: At a temperature of the phase transformation temperature T of the high-temperature titanium alloy minus (30 to 50 °C), solution treatment of the high-temperature titanium alloy is carried out for 1 h to 4 h; the high-strength titanium alloy is not heat-treated; then the two blanks are machined into pre-weld blanks; β - At a temperature of the phase transformation temperature T of the high-temperature titanium alloy minus (30 to 50 °C), solution treatment of the high-temperature titanium alloy is carried out for 1 h to 4 h; the high-strength titanium alloy is not heat-treated; then the two blanks are machined into pre-weld blanks; Step 3: Inertial friction welding: Fix the two titanium alloy blanks prepared in Step 2 on the inertial friction welding equipment, and use them as the rotating end and the advancing end of inertial friction welding respectively. Carry out inertial friction welding according to the set process to obtain a high-temperature / high-strength dual-titanium alloy blank; Carry out inertial friction welding on the two blanks at a rotational speed of 200 r / min to 750 r / min, and hold the upset pressure for 10 s to 40 s after welding; Step 4: Multi-step heat treatment: At a temperature of the phase transformation temperature T of the high-strength titanium alloy β -(30 - 50 °C), first perform solution treatment on the double titanium alloy blank obtained in Step 3 for 1 h to 4 h, cool to room temperature, and then perform aging treatment at a temperature of 550 °C to 750 °C for 2 h to 8 h to obtain a high-temperature / high-strength double titanium alloy gradient structure.

2. The method for preparing a high-temperature / high-strength dual-titanium alloy gradient structure composite according to claim 1, wherein: In Step 2, after the solution treatment of the high-temperature titanium alloy, it is cooled to room temperature by oil cooling or air cooling.

3. The method for compound preparation of a high-temperature / high-strength dual-titanium alloy gradient structure according to claim 1, characterized in that: In Step 4, it is cooled to room temperature by oil cooling or air cooling.

4. A system for the composite preparation method of the high-temperature / high-strength dual titanium alloy gradient structure according to any one of claims 1-3, characterized in that: It includes a blank forging module, a heat treatment module, and an inertial friction welding module; The blank is heated and forged through the blank forging module; The high-temperature titanium alloy forged in Step 1 is solution-treated through the heat treatment module, and the dual-titanium alloy blank obtained in Step 3 is solution-treated; The two titanium alloy blanks prepared in Step 2 are subjected to inertial friction welding through the inertial friction welding module.

Images