A method for simultaneous age hardening of hot isostatic pressed diffusion bonded high temperature alloys and copper alloys

Abstract

The application discloses a hot isostatic pressing diffusion connection synchronous aging treatment method for high-temperature alloy and copper alloy, relates to the field of dissimilar metal solid-phase welding, and can improve the strength of the high-temperature alloy, inhibit size distortion caused by stress change in the aging process, improve machining precision, shorten the process cycle of finished products and greatly improve production efficiency. Step 1: high-temperature alloy with a predetermined structure is prepared, and solid solution treatment is carried out; step 2: copper alloy with a predetermined structure is prepared, the surfaces of the high-temperature alloy and the copper alloy are polished smooth and cleaned; step 3: the copper alloy and the high-temperature alloy structure are attached to the surfaces to be connected, and vacuum sealing is carried out; step 4: the structure after sealing is sent into a hot isostatic pressing furnace to carry out hot isostatic pressing diffusion connection and in-furnace aging treatment, so that a final product is obtained. According to the hot isostatic pressing diffusion connection synchronous aging treatment method, the strength of the high-temperature alloy is improved, size distortion is inhibited, machining precision is improved, the process cycle of finished products is shortened, and production efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of solid-state welding of dissimilar metals, and more specifically to a method for simultaneous aging treatment of hot isostatic diffusion bonding of high-temperature alloys and copper alloys. Background Technology

[0002] With the development of aerospace technology, single high-temperature alloy materials can no longer meet the needs of modern aerospace technology. Often, it is necessary to prepare bimetallic structures by welding dissimilar materials to achieve high performance requirements.

[0003] For example, copper and copper alloys possess excellent thermal and electrical conductivity. Connecting copper to high-temperature alloys can meet the high-performance requirements of aerospace components while simultaneously enhancing heat dissipation and reducing costs. High-temperature alloys, after solution treatment and aging, exhibit good strength, corrosion resistance, and high-temperature mechanical properties. Therefore, high-temperature alloys are widely used in the aerospace field.

[0004] For precipitation-strengthened superalloys, solution aging is a common heat treatment method to improve their properties. After solution treatment, the superalloy obtains a supersaturated solid solution. During subsequent aging, a second phase precipitates from the supersaturated solid solution and disperses in the matrix to form a precipitate. This precipitate effectively inhibits the movement of grain boundaries and dislocations, optimizing the mechanical properties of the superalloy. However, aging alters the internal stress state of the components, making them prone to defects such as dimensional distortion.

[0005] The existing hot isostatic pressing (HIP) process involves placing the workpiece in a sealed container, using inert gases such as nitrogen or argon as the pressure transmission medium, and applying isotropic pressure to the workpiece under the combined action of high temperature and high pressure, thus pressing and sintering the workpiece. Because the workpiece is subjected to uniform pressure in all directions, the product exhibits advantages such as high density, good uniformity, and excellent performance under the combined action of high temperature and high pressure. The HIP diffusion bonding process can significantly improve defects such as porosity and shrinkage cavities in the workpiece while completing the bonding process, thereby improving various performance characteristics. Effective welding of high-temperature alloys and copper alloys is achieved through HIP diffusion bonding, avoiding defects such as porosity and looseness present in traditional welding, thus improving the mechanical properties and service life of the product. Currently, the conventional process for bonding high-temperature alloys and copper alloys involves solution aging of the high-temperature alloy, diffusion bonding in a vacuum diffusion furnace, and HIP treatment. This process involves many steps, a long cycle, poor process controllability, and is prone to stress concentration, leading to a decrease in the material's mechanical properties and corrosion resistance. Furthermore, experience shows that the longer the workpiece remains between leaving the factory and aging treatment, the worse the mechanical properties of the final product.

[0006] Chinese invention patent application CN116689929A ​​discloses a hot isostatic pressing (HIP) diffusion bonding method for copper and stainless steel. The method involves surface treatment of the copper and stainless steel surfaces to be bonded to ensure a smooth, impurity-free surface. The copper and stainless steel are then assembled within a sheath and placed in a vacuum degassing furnace, heated to 300-350°C, and held for 3-5 hours. During this process, the sheath is evacuated to create a seal. HIP diffusion bonding is then performed, followed by solution aging after furnace cooling. The advantage of this method is that the vacuum stage effectively removes moisture and oxygen from the sheath, reducing the production of hydrides and oxides in the subsequent HIP stage, thus effectively improving the tensile strength and weld bonding rate of the product. However, a separate solution aging treatment is required after HIP, resulting in a longer production cycle. Furthermore, metal precipitation is prone to occur during the aging transition period, affecting the final product quality.

[0007] Chinese invention patent application CN108544074A discloses a diffusion bonding method for a high-temperature alloy and an oxygen-free copper ring. The method involves manufacturing a copper sheath based on the high-temperature alloy ring, with the sheath thickness exceeding the copper layer thickness of the connector by a certain machining allowance. The surfaces of the high-temperature alloy ring and the copper sheath are polished and ultrasonically cleaned with acetone. The sheath is then vacuum electron beam welded and placed in a hot isostatic pressing (HIP) apparatus for diffusion bonding. Excess oxygen-free copper is removed by subsequent machining. This method effectively avoids problems such as peeling, spalling, delamination, and separation from the substrate in the bonding layer, reducing the porosity of the bonding layer and achieving good metallurgical bonding. However, this method directly performs HIP diffusion bonding after preparing the high-temperature alloy ring without solution aging treatment. This can easily lead to problems such as precipitated phases, grain refinement, and stress concentration in the high-temperature alloy, affecting the final product performance. Summary of the Invention

[0008] To address the above problems, this invention proposes a method for simultaneous aging treatment of hot isostatic pressing diffusion bonding of high-temperature alloys and copper alloys. This method can improve the strength of high-temperature alloys while suppressing dimensional distortion caused by stress changes during aging through the diffusion pressure of hot isostatic pressing diffusion bonding, thereby improving processing accuracy, shortening the process cycle of finished products, and significantly improving production efficiency.

[0009] The technical solution of the present invention includes the following steps:

[0010] Step 1: Prepare a high-temperature alloy with a predetermined structure and perform a solution treatment;

[0011] Step 2: Prepare a copper alloy with the predetermined structure, and polish and clean the surfaces of the high-temperature alloy and the copper alloy.

[0012] Step 3: Keep the copper alloy obtained in Step 2 in contact with the surfaces to be joined in the high-temperature alloy structure, and perform vacuum sealing welding;

[0013] Step 4: The vacuum-sealed structural components are sent into a hot isostatic pressing furnace for hot isostatic diffusion bonding and furnace aging treatment, including: sequentially heating and pressurizing, holding at high temperature, holding at pressure and cooling in the furnace, and depressurizing and removing the components after cooling to room temperature.

[0014] The heating rate during the heating and pressurization process is 5–10 °C / min, and the temperature is raised to 750–850 °C.

[0015] During the heating and pressurization process, the pressure is increased to 100-150 MPa, then the pressurization is stopped, and the heat and pressure holding process begins.

[0016] The high-temperature section is kept under pressure for 1 to 4 hours. After the furnace is kept under pressure and cooled down to room temperature, the pressure is released and the parts are removed to obtain the finished product.

[0017] Furthermore, the specific steps of the solution treatment in step 1 are as follows: after heating the high-temperature treatment furnace to the solution temperature, quickly put the high-temperature alloy into the heat treatment furnace, hold it at the temperature for 5 to 60 minutes, and then take out the high-temperature alloy and cool it to room temperature with water.

[0018] Further, step 2 specifically involves: using 120#, 400#, and 800# sandpaper to progressively polish the interfaces of the high-temperature alloy and copper alloy to be joined, then immersing them in dilute hydrochloric acid, followed by ultrasonic cleaning in alcohol, drying with cold air, and finally sealing and storing the cleaned parts.

[0019] Furthermore, step 3 specifically involves: fully bonding the connecting surface of the copper alloy strip with the connecting surface of the high-temperature alloy part, and then vacuum sealing it.

[0020] Furthermore, in step 4, the heating rate during the heating and pressurization process is 5–10 °C / min, and the temperature is increased to 750–850 °C.

[0021] Furthermore, in step 4, argon gas is introduced as a pressure medium to raise the temperature and pressure. The pressure rises to 100-150 MPa and then the pressure increase is stopped, and the heat preservation and pressure maintenance process begins.

[0022] Furthermore, in step 4, the furnace pressure must be maintained during furnace cooling, and the pressure should be released and the parts removed after the temperature drops to room temperature.

[0023] Furthermore, in step 4, multiple connecting parts can be simultaneously fed into a hot isostatic pressing furnace for hot isostatic pressing treatment.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The hot isostatic pressing diffusion bonding and simultaneous aging process for high-temperature alloys and copper alloys provided by this invention directly performs hot isostatic pressing diffusion bonding and aging treatment on the high-temperature alloys and copper alloys in a hot isostatic pressing equipment. This simplifies the traditional process of solution treatment, vacuum diffusion bonding, hot isostatic pressing densification, and artificial aging into a new process of solution treatment and hot isostatic pressing diffusion bonding. This eliminates the need for separate aging of the bonding components, shortens the production cycle, and saves production costs.

[0026] II. The hot isostatic pressing diffusion bonding process for high-temperature alloys and copper alloys provided by this invention allows for simultaneous aging treatment of the connectors during hot isostatic pressing diffusion bonding, eliminating the aging transition time and preventing the metal from precipitating out of the high-temperature alloys. This results in high-performance connectors and lays the foundation for improving the quality of dissimilar metal bonding.

[0027] Third, the hot isostatic pressing diffusion bonding and synchronous aging process method for high-temperature alloys and copper alloys provided by the present invention suppresses dimensional distortion caused by stress changes during aging through the diffusion pressure of hot isostatic pressing diffusion bonding, thereby improving the machining accuracy.

[0028] Fourth, unlike the traditional method of performing solution aging treatment separately after hot isostatic pressing (HIP) or before HIP, this invention takes into account the fact that the aging temperature of high-temperature alloys is similar to that of HIP diffusion bonding. Instead, it performs solution aging treatment on the high-temperature alloy separately before HIP, and performs co-furnace aging treatment on the connectors during HIP. The simultaneous HIP diffusion bonding and aging treatment can significantly save time and reduce costs. Attached Figure Description

[0029] Figure 1 This is a deep drawing diagram of a high-temperature alloy ribbed thin-walled structural part manufactured using the hot isostatic pressing diffusion bonding and synchronous aging treatment process for high-temperature alloys and copper alloys provided by the present invention. It includes a high-temperature alloy ribbed wall plate 1, a copper alloy thin plate 2, and a deep drawing upper die 3.

[0030] Figure 2 This is a schematic diagram of hot isostatic pressing assembly for manufacturing high-temperature alloy ribbed thin-walled structural parts using the hot isostatic pressing diffusion bonding and synchronous aging treatment process of high-temperature alloy and copper alloy provided by the present invention. It includes a high-temperature alloy ribbed wall plate 1 and a copper alloy thin plate 2 that are bonded together after deep drawing, a lower sleeve 4 and an upper sleeve 5.

[0031] Figure 3 This is a schematic diagram of a finished high-temperature alloy ribbed thin-walled structural component manufactured using the hot isostatic pressing diffusion bonding and synchronous aging treatment process for high-temperature alloys and copper alloys provided by this invention.

[0032] Figure 4A schematic diagram of a porous bimetallic rotor plunger assembly manufactured using the hot isostatic diffusion bonding and synchronous aging process for high-temperature alloys and copper alloys provided by this invention is shown, including a porous bimetallic rotor plunger 6 and a tin bronze cylindrical component 7.

[0033] Figure 5 A schematic diagram of a porous bimetallic rotor plunger manufactured using the hot isostatic pressure diffusion bonding and synchronous aging treatment process for high-temperature alloys and copper alloys provided by this invention. Detailed Implementation

[0034] To clearly illustrate the technical features of this patent, the following detailed descriptions of three embodiments employing the method of this patent, in conjunction with the accompanying drawings, will be provided. Example 1:

[0035] like Figures 1-3 As shown, in this embodiment, GH4099 high-temperature alloy and T2 copper are used, and the processing target is a ribbed thin-walled structural component. The method for manufacturing ribbed thin-walled structural components using the hot isostatic pressing diffusion bonding and simultaneous aging treatment process of high-temperature alloy and copper alloy includes the following steps:

[0036] Step 1: Prepare GH4099 high-temperature alloy stiffened wall plate 1 with a predetermined structure and perform solution treatment;

[0037] The high-temperature treatment furnace is heated to the solution temperature of 1140-1170℃. After reaching the target temperature, the ribbed thin-walled part 1 made of GH4099 high-temperature alloy is quickly placed into the heat treatment furnace. After holding at the temperature for 5-60 minutes, the GH4099 high-temperature alloy ribbed wall plate 1 is taken out and water-cooled to room temperature.

[0038] Step 2: Prepare the T2 copper sheet 2 with the predetermined structure, polish the surface of the GH4099 high temperature alloy ribbed wall plate 1 and the T2 copper sheet 2 to a smooth finish and clean them.

[0039] Step 3: Use a sleeve and seal welding method to keep the copper alloy obtained in step 2 in contact with the surfaces to be connected in the high-temperature alloy structure;

[0040] First, the deep drawing die 3 is designed according to the structure of the GH4099 high temperature alloy ribbed thin-walled part 1. Considering that the GH4099 high temperature alloy ribbed thin-walled part 1 has multiple arrayed receiving grooves on one side, the deep drawing die 3 needs to be adapted to the receiving grooves. Therefore, the die 3 has multiple block structures, which correspond one-to-one with the receiving grooves. During deep drawing, the T2 copper thin plate 2 is drawn and pressed into the receiving groove to fit the surface of the high temperature alloy.

[0041] Then, as Figure 1As shown, using T2 copper sheet 2 as the original blank and GH4099 high-temperature alloy ribbed wall plate 1 as the lower die, the T2 copper sheet 2 is placed centrally on the upper surface of the GH4099 high-temperature alloy ribbed wall plate 1. The T2 copper sheet 2 is drawn into shape using a deep drawing process, fitting it to the inner surface of the receiving groove of the GH4099 high-temperature alloy ribbed wall plate 1. Excess copper is removed by machining, resulting in... Figure 3 The structural component shown;

[0042] Finally, based on the obtained structural components, the design dimensions of the enclosure are determined. This enclosure includes an upper enclosure 4 and a lower enclosure 5. When closed, the two enclosures enclose the structure of the ribbed thin-walled component 1 and the entire outer wall of the T2 copper connector 2. The thickness of the enclosure should be based on the thickness of the formed connector plus a certain machining allowance. Boron nitride is sprayed onto the lower side of the upper enclosure 4 and the inner side of the lower enclosure 5. The obtained structural components are then placed inside the enclosures and vacuum-sealed.

[0043] Step 4: The vacuum-sealed structural components, along with the upper and lower sheaths, are placed together in a hot isostatic pressing furnace for hot isostatic diffusion bonding. The assembly method is as follows: Figure 2 As shown;

[0044] The cladding obtained in step 4 is placed in a hot isostatic pressing furnace, and argon gas is introduced as the pressure medium. The temperature is raised to 750-850℃ at 5-10℃, and the pressure is increased to 120-140MPa. The temperature is held for 1-2 hours. Then, the furnace is cooled down while maintaining the pressure. After the temperature drops to room temperature, the pressure is released and the part is removed. At the same time, the diffusion bonding of the ribbed thin-walled part and T2 copper and the aging treatment of the high-temperature alloy are achieved.

[0045] During unloading, the package obtained in step 4 is cut open to obtain the final product as shown. Figure 3 . Example 2:

[0046] like Figures 1-3 As shown, in this embodiment, the GH4099 high-temperature alloy and copper are used to process ribbed thin-walled structural components. The method for manufacturing ribbed thin-walled structural components using the hot isostatic pressing diffusion bonding and simultaneous aging treatment process of the high-temperature alloy and copper alloy includes the following steps:

[0047] Step 1: Prepare GH4099 high-temperature alloy stiffened wall plate 1 with a predetermined structure and perform solution treatment;

[0048] The high-temperature treatment furnace is heated to the solution temperature of 1140-1170℃. After reaching the target temperature, the ribbed thin-walled part 1 made of GH4099 high-temperature alloy is quickly placed into the heat treatment furnace. After holding at the temperature for 5-60 minutes, the GH4099 high-temperature alloy ribbed wall plate 1 is taken out and water-cooled to room temperature.

[0049] Step 2: Prepare a copper sheet 2 with a predetermined structure. Polish the surfaces of the GH4099 high-temperature alloy ribbed wall plate 1 and the copper sheet 2 until smooth and clean.

[0050] Step 3: Use diffusion bonding to maintain the adhesion between the copper alloy obtained in Step 2 and the surfaces to be bonded in the high-temperature alloy structure;

[0051] First, the deep drawing die 3 is designed according to the structure of the GH4099 high temperature alloy ribbed thin-walled part 1. Considering that one side of the GH4099 high temperature alloy ribbed thin-walled part 1 has multiple arrayed receiving grooves, the deep drawing die 3 needs to be adapted to the receiving grooves. Therefore, the die 3 has multiple block structures, which correspond one-to-one with the receiving grooves. During deep drawing, the copper sheet 2 is drawn and pressed into the receiving groove to fit the surface of the high temperature alloy.

[0052] Then, as Figure 1 As shown, using a thin copper sheet 2 as the original blank and a GH4099 high-temperature alloy ribbed wall plate 1 as the lower die, the thin copper sheet 2 is placed centrally on the upper surface of the GH4099 high-temperature alloy ribbed wall plate 1. The copper sheet 2 is then drawn using a deep-drawing process to form a shape that fits against the inner surface of the GH4099 high-temperature alloy ribbed wall plate 1 receiving groove, resulting in... Figure 3 The structural component shown;

[0053] Finally, the resulting structural component is placed in a vacuum sintering furnace, with the graphite mold serving as the upper and lower pressure heads, and a vacuum is drawn to 10. -3 Pa, the temperature is raised from 5 to 10°C to 850 to 900°C and then pressurized to 3 to 5 MPa. The temperature and pressure are maintained for 1 to 2 hours. After that, the part is taken out after being cooled to room temperature in the furnace. At the same time, the diffusion connection between the upper surface of the rib of the thin-walled part 1 and the copper and the aging treatment of the high-temperature alloy are achieved.

[0054] Step 4: Place the GH4099 high-temperature alloy and copper connector obtained in Step 3 into a hot isostatic pressing furnace, fill it with argon gas as the pressure medium, raise the temperature to 750-850℃ at 5-10℃, pressurize it to 100-150MPa, hold it at the temperature for 1-2 hours, and then cool it down with the furnace while maintaining the pressure. After it has cooled to room temperature, release the pressure and take out the parts.

[0055] During unloading, machining removes excess copper from the surface of the finished product obtained in step 5, resulting in the final product as shown. Figure 3 . Example 3:

[0056] like Figures 4-5 As shown, in this embodiment, high-temperature alloy steel and tin bronze are used, and the processing target is a rotor plunger. The method for manufacturing a high-temperature alloy steel porous bimetallic rotor plunger and tin bronze connector using the hot isostatic pressing diffusion bonding and simultaneous aging treatment process of high-temperature alloy and copper alloy includes the following steps:

[0057] Step 1: Prepare a high-temperature alloy steel porous bimetallic rotor plunger 6 with a predetermined structure and perform a solution treatment;

[0058] The high-temperature treatment furnace is heated to the solution temperature of 980-1020℃. After reaching the target temperature, the porous bimetallic rotor plunger 6 made of high-temperature alloy steel is quickly placed into the heat treatment furnace. After holding at the temperature for 5-60 minutes, the porous bimetallic rotor plunger 6 is taken out and cooled to room temperature with water.

[0059] Step 2: Prepare the tin bronze cylinder 7 with the predetermined structure, and polish and clean the surfaces of the porous bimetallic rotor plunger 6 and the tin bronze cylinder 7 to be connected.

[0060] Step 3: Use diffusion bonding to keep the surface to be bonded of the tin bronze cylinder 7 obtained in step 2 in contact with the surface to be bonded of the porous bimetallic rotor plunger 6;

[0061] Tin bronze cylinders 7 are inserted one-to-one into the holes of the porous bimetallic rotor plunger 6. The resulting structural components are then placed in a vacuum sintering furnace, with a graphite mold serving as the upper and lower pressure heads. A vacuum of 10 is then applied. -3 Pa, the temperature is raised to 850-900℃ at 5-10℃ and then pressurized to 3-5MPa, and held at the temperature and pressure for 1-2 hours. After that, the part is taken out after being cooled to room temperature in the furnace. At the same time, the diffusion connection between the cap of the tin bronze cylinder 7 and the upper surface of the porous bimetallic rotor plunger 6 is achieved, and the aging treatment of the high temperature alloy is completed.

[0062] Step 4: Place the porous bimetallic rotor plunger 6 and the tin bronze cylinder 7 obtained in Step 3 into a hot isostatic pressing furnace, fill it with argon gas as the pressure medium, raise the temperature to 750-850°C at 5-10°C, pressurize it to 100-150MPa, hold it at the temperature for 1-4 hours, and then lower the temperature along with the furnace while maintaining the pressure. After it has cooled to room temperature, release the pressure and take out the parts.

[0063] During unloading, the finished product obtained in step 4 is taken out, and the tin bronze on the upper surface brim is removed by machining to obtain the final finished product as shown. Figure 5 .

[0064] There are many specific ways to implement this invention. The above description is only a preferred embodiment of this invention. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of this invention, and these improvements should also be considered within the scope of protection of this invention.

Claims

1. A method for simultaneous aging treatment of hot isostatic pressing diffusion bonding of high-temperature alloys and copper alloys, characterized in that, Includes the following steps: Step 1: Prepare a high-temperature alloy with a predetermined structure and perform a solution treatment; The specific steps of the solution treatment in step 1 are as follows: heat the high-temperature treatment furnace to the solution temperature, and after reaching the solution temperature, quickly put the high-temperature alloy into the heat treatment furnace and hold it for 5 to 60 minutes. Then take out the high-temperature alloy and cool it to room temperature with water. Step 2: Prepare a copper alloy with the predetermined structure, and polish and clean the surfaces of the high-temperature alloy and the copper alloy. Step 3: Keep the copper alloy obtained in Step 2 in contact with the surfaces to be joined in the high-temperature alloy structure, and perform vacuum sealing welding; Step 4: Send the welded structural components into a hot isostatic pressing furnace for hot isostatic diffusion bonding and furnace aging treatment, including: sequentially heating and pressurizing, holding the temperature and pressure in the high-temperature section, holding the pressure and cooling in the furnace, and depressurizing and removing the components after cooling to room temperature. The heating rate during the heating and pressurization process is 5–10 °C / min, and the temperature is raised to 750–850 °C. During the heating and pressurization process, the pressure is increased to 100-150 MPa, then the pressurization is stopped, and the heat and pressure holding process begins. The high-temperature section is kept under pressure for 1 to 4 hours. After cooling to room temperature in the furnace, the pressure is released and the parts are removed to obtain the finished product. In step 4, argon gas is introduced as a pressure medium to raise the temperature and pressure. The pressure rises to 100-150 MPa and then the pressure increase is stopped, and the heat preservation and pressure holding process begins. In step 4, maintain pressure during the furnace cooling process, and release pressure and remove the parts after cooling to room temperature.

2. The method for simultaneous aging treatment of hot isostatic pressing diffusion bonding of high-temperature alloys and copper alloys according to claim 1, characterized in that, Step 2 is as follows: Use 120#, 400#, and 800# sandpaper to polish the interfaces of the high-temperature alloy and copper alloy to be joined step by step, then soak them in dilute hydrochloric acid, then ultrasonically clean them in alcohol, blow them dry with cold air, and seal and store the cleaned parts.

3. The method for simultaneous aging treatment of hot isostatic pressing diffusion bonding of high-temperature alloys and copper alloys according to claim 1, characterized in that, Step 3 specifically involves: fully bonding the copper alloy surface to be connected with the high-temperature alloy surface to be connected, and then vacuum sealing it.

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