Preparation method and application of SPS for sintering and connecting TZM and graphite by using titanium hydride powder

Abstract

The invention discloses an SPS preparation method and application for sintering and connecting TZM and graphite by using titanium hydride powder in the field of connection of TZM / graphite dissimilar materials, and particularly relates to a TZM / graphite composite material obtained by performing sintering diffusion connection on the TZM and graphite dissimilar materials by using the titanium hydride powder as a middle layer material through an SPS technology. The method has the following advantages that the titanium hydride powder serves as an interlayer material, compared with existing used titanium powder or titanium foil, the titanium hydride powder is environmentally friendly and low in component content, the titanium hydride powder can release hydrogen and generate elemental titanium within the temperature range of 400-800 DEG C, oxidation of titanium can be reduced while a base metal oxide layer can be removed, interdiffusion and solid solution of interface Mo and Ti atoms are promoted, and the service life of the interface Mo and Ti is prolonged. And a good metallurgical bonding interface is formed through reaction with the graphite side, and the TZM / graphite composite material which is free of crack defects, high in interface bonding strength and good in durability is obtained.

Description

Technical Field

[0001] The present invention relates to the field of TZM / graphite dissimilar material connection, and in particular to an SPS preparation method and application for sintering and connecting TZM and graphite by using titanium hydride powder. Background Art

[0002] TZM alloys are high-temperature resistant molybdenum alloys that incorporate trace amounts of elements such as Ti, Zr, and C to form solid solutions such as Mo-Ti and Mo-Zr, and dispersion-strengthened second phases such as TiC, ZrC, and ZrO2. The presence of these solid solutions and second-phase particles effectively inhibits grain growth, maintaining a fine grain structure. Furthermore, the presence of these second-phase particles significantly enhances the strength and ductility of the TZM alloy by suppressing dislocation motion. TZM alloys exhibit excellent properties such as a high melting point, low coefficient of expansion, low creep rate, and high thermal and electrical conductivity. They are widely used in reflective screens for nuclear fusion devices, vacuum components, and X-ray tube target discs. Graphite, a low-atomic-weight material with a high melting point, low density, and excellent heat dissipation, has attracted widespread attention as a novel composite material combining TZM alloys with graphite. These composites offer both strength and heat dissipation and storage properties while significantly reducing workpiece weight within the same volume, making them ideal for use in high-temperature and high-speed rotational environments, such as the anode target disc component within CT X-ray tubes.

[0003] Since TZM alloy and graphite are heterogeneous materials, the main connection methods currently used include high-temperature vacuum brazing, vacuum diffusion welding, SPS diffusion welding, etc. For example, patent publication number CN102240836A discloses a method for vacuum brazing of molybdenum and graphite, which uses NiCoPaTi foil as the brazing material to vacuum braze molybdenum and graphite, and obtains a room temperature interface shear strength of up to 16 MPa. For example, patent publication number CN108161156A discloses a vacuum brazing method for molybdenum alloy and graphite, which uses TiCrTa foil to vacuum braze the molybdenum alloy and graphite, and the room temperature shear strength of the interface is up to 21 MPa. For another example, patent publication number CN111014869A discloses a vacuum welding method for molybdenum-based graphite, which discloses preparing porous TZM, and then using titanium powder or zirconium powder to sinter the porous TZM and graphite in a vacuum hot pressing furnace. The room temperature strength of the interface is up to 21 MPa. The above brazing process is long and the strength is not high. For example, patent publication number CN113770467A discloses a method for SPS pressureless brazing of TZM alloy and graphite, which uses titanium foil to perform SPS pressureless brazing of TZM and graphite, and the obtained room temperature interface shear strength is 55 MPa. However, when subjected to pressure, it is easy to cause excessive loss of solder. For example, patent publication number CN109048030B discloses a method for SPS diffusion welding of dissimilar materials of TZM and graphite, specifically disclosing the use of titanium foil to perform SPS diffusion welding of TZM alloy and graphite. The room temperature interface shear strength is up to 49 MPa, but due to the long welding time, it is easy to cause the performance of the parent material to deteriorate.

[0004] Therefore, in order to solve the above problems, the present invention adopts SPS technology to sinter and connect TZM alloy / titanium hydride powder / graphite, so as to ensure that a composite material with excellent interface performance can be obtained under a certain pressure state. Summary of the Invention

[0005] Aiming at the existing welding system of TZM alloy and graphite heterogeneous materials, the present invention provides an SPS preparation method and application for sintering and connecting TZM and graphite by using titanium hydride powder.

[0006] The present invention achieves the above-mentioned purpose through the following technical solutions: As a first aspect of the present invention, a method for preparing SPS by sintering and connecting TZM and graphite using titanium hydride powder is provided, comprising the following steps: Step 1: Grind, ultrasonically clean, dry with nitrogen, and heat and keep warm under vacuum conditions on the surfaces to be welded of TZM and graphite; Step 2: heating the titanium hydride powder under vacuum conditions and keeping the temperature constant; Step 3: Place the processed TZM, titanium hydride powder and graphite in the graphite mold from bottom to top, and press the upper and lower ends of the graphite mold with a graphite press head; Step 4: Place the graphite mold assembled in step 3 in the furnace of the spark plasma sintering system, apply axial pressure, evacuate, and then pass a DC pulse current to sinter and diffuse the TZM and graphite.

[0007] As a further optimization scheme of the present invention, in step 1, the surface to be welded of the TZM alloy block is first mechanically polished using 400, 1000 and 2000 mesh sandpaper in sequence to remove surface impurities and oxide layer, and then ultrasonically cleaned using anhydrous ethanol, alkali solution with a pH of 7-7.5, and pure water in sequence, and then dehydrated using anhydrous ethanol and dried with nitrogen. The treated TZM alloy block is placed in a high-temperature vacuum heat treatment furnace and evacuated to 5×10 -3 Pa, and heated to 1400 ° C, and kept warm for 30 minutes to further remove impurities and oxide layers on the TZM surface.

[0008] As a further optimization scheme of the present invention, in step 1, the graphite is first ultrasonically cleaned with pure water and blown dry with nitrogen, and then the treated graphite is placed in a vacuum oven, evacuated, heated to 100° C., and kept warm for 5 hours.

[0009] As a further optimization solution of the present invention, in step 2, the titanium hydride powder is placed in a vacuum oven, evacuated, and then heated to 70° C. and kept warm for 1 hour.

[0010] As a further optimization solution of the present invention, in step 2, the titanium hydride powder has a Fisher particle size of 1-30 μm and a purity of ≥99.5%. More preferably, the titanium hydride powder has a Fisher particle size of 1-4 μm.

[0011] As a further optimization solution of the present invention, in step 4, an axial pressure of 10 MPa is applied to the upper and lower pressure heads of the graphite mold, and the pressure is evacuated to 5 Pa.

[0012] As a further optimization solution of the present invention, in step 4, the sintering and diffusion bonding process of TZM and graphite dissimilar materials is segmented heating, and the specific settings are as follows: The first stage is the purification and degassing stage: The axial pressure is 10 MPa; the heating rate is 5-10°C / min, the degassing temperature is 800-1000°C, and the holding time is 30-60 min; The second stage is the diffusion connection stage: Axial pressure: pressurize at a rate of 0.2-0.5 MPa / min to the connection temperature, the pressure is 30 MPa, and the heating rate is 10-15 ° C / min; The connection temperature is 1500-1600℃ and the holding time is 5-20min.

[0013] The third stage is the cooling stage: The cooling method is load cooling, first cooling to 1000℃ at a cooling rate of 5-10℃ / min, then cooling to 500℃ at a cooling rate of 10-15℃ / min, and finally cooling with the furnace.

[0014] As a further optimization scheme of the present invention, the temperature and holding time of the purification and degassing stage are related to the purity and air absorption volume of the titanium hydride powder and graphite raw materials. The platform temperature and holding time of degassing are determined according to the vacuum degree of the equipment. The degassing temperature is preferably 900°C and the holding time is preferably 30 minutes.

[0015] As a second aspect of the present invention, there is also provided a TZM / graphite composite material prepared by the SPS preparation method as described in any one of the above.

[0016] As a further optimization solution of the present invention, the room temperature interface shear strength of the TZM / graphite composite material is ≥50 MPa.

[0017] The beneficial effects of the present invention are: (1) The present invention uses titanium hydride powder as an intermediate layer material for sintering and diffusion bonding of TZM and graphite dissimilar materials. Compared with the titanium powder used in the prior art, titanium hydride powder releases hydrogen and generates elemental titanium in the range of 400-800°C, which can remove the oxide layer of the parent material while reducing the oxidation of titanium, promote the mutual diffusion and solid solution of Mo and Ti atoms at the interface, and react with the graphite side to form a good metallurgical bonding interface. Compared with the titanium foil used in the prior art, the present invention can reduce the problem of insufficient solder in the interface layer due to excessive extrusion of the interface due to deformation and softening of the titanium foil during the sintering heating and pressurizing process, and reduce the pickling process required for conventional titanium foil use. It is environmentally friendly and low in cost.

[0018] (2) The present invention adopts SPS sintering technology to sinter and diffusely bond TZM and graphite dissimilar materials. Due to the large specific surface area of ​​the powder and the large contact area between TZM and graphite, the SPS technology has an activation effect on the powder surface, and can complete the densification of the intermediate layer powder and the atomic diffusion and reaction process between the interfaces in a short time, thereby obtaining a TZM / graphite composite material with no crack defects, high interface bonding strength and good durability. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is an SEM image of the interface of the TZM / graphite composite material prepared in Example 2; Figure 2This is the interface element surface scanning result of the TZM / graphite composite material prepared in Example 2; Figure 3 Statistics of interface element content of the TZM / graphite composite material prepared in Example 2; Figure 4 The test results of room temperature interface shear strength of TZM / graphite composites; Figure 5 Thermal shock test results of TZM / graphite composites. DETAILED DESCRIPTION

[0020] The present application is described in further detail below in conjunction with the accompanying drawings. It is necessary to point out that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technicians in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0021] The spark plasma sintering furnace used in the following examples is a LABOX-350 series spark plasma sintering system produced by Sinter Land Co., Ltd. of Japan. The current type is a direct current pulse current with a pulse sequence of 40:7.

[0022] The TZM alloy used in the following examples is in a forged state, and the graphite is high-strength graphite. The composition of the TZM alloy is 0.4-0.6wt% Ti, 0.07-0.12wt% Zr, and 0.01-0.04wt% C, with the remainder being Mo (excluding impurities); the carbon content of the graphite is greater than 99.99%.

[0023] Example 1 This embodiment discloses a SPS preparation method for sintering and connecting a TZM alloy block and graphite using titanium hydride powder. The specific steps are as follows: Step 1: First, the welding surface of the Φ20mm×2mm TZM alloy block is mechanically polished with 400, 1000 and 2000 grit sandpaper in sequence, and then ultrasonically cleaned with anhydrous ethanol, alkali solution with a pH of 7-7.5 (Lanfei aluminum alloy cleaning solution) and pure water in sequence, and then dehydrated with anhydrous ethanol and dried with nitrogen. The treated TZM alloy block is placed in a high-temperature vacuum heat treatment furnace and vacuumed to 5×10 -3 Pa, and heat to 1400℃, keep warm for 30min, then cool to room temperature and take out; Step 2: Use pure water to ultrasonically clean the Φ20mm×2mm graphite block, blow dry with nitrogen, put it into a vacuum oven, evacuate to 50Pa, heat to 100℃, and keep warm for 5h; Step 3: Weigh 0.5 g of titanium hydride powder (Ferris particle size of 1-4 μm, purity ≥99.5%) and place it in a vacuum oven. After evacuating, heat to 70°C at 50 Pa and keep warm for 1 hour. Step 4: Place the processed TZM alloy block, titanium hydride powder and graphite in a graphite mold from bottom to top, and press the upper and lower ends of the graphite mold with a graphite press to obtain a graphite mold containing the parts to be welded; Step 5: After wrapping a layer of carbon felt on the outside of the mold, place it in the furnace chamber of the spark plasma sintering furnace, apply 10MPa axial pressure to the upper and lower graphite pressure heads, evacuate to 5Pa, and then pass a DC pulse current to sinter and diffuse the TZM and graphite dissimilar materials. The process is segmented heating: The first stage is the purification and degassing stage: The axial pressure is 10 MPa, the heating rate is 8°C / min, the degassing temperature is 900°C, and the holding time is 30 min. The second stage is the diffusion connection stage: Axial pressure: pressurize at a rate of 0.2-0.5 MPa / min to the connection temperature, the pressure is 30 MPa; the heating rate is 12 ° C / min, the connection temperature is 1550 ° C, and the holding time is 20 minutes; The third stage is the cooling stage: The cooling method is loaded cooling with a cooling rate of 8°C / min to 1000°C and 12°C / min to 500°C, and then furnace cooling to obtain TZM / graphite composite material.

[0024] Example 2 This embodiment discloses an SPS preparation method for sintering and connecting a TZM alloy block and graphite using titanium hydride powder. The difference from Example 1 lies in the different segmented heating process in step 5, specifically the diffusion bonding stage: Axial pressure: When pressurized to the connection temperature at a pressurization rate of 0.2-0.5 MPa / min, the pressure is 30 MPa, the heating rate is 12°C / min, the connection temperature is 1570°C, and the holding time is 10 minutes.

[0025] Figure 1 This is the SEM image of the interface of the TZM / graphite composite material obtained in Example 2. Figure 1In the figure, the black area represents graphite, with a small amount of titanium within. This is due to the diffusion of melted titanium through the graphite pores during welding, forming islands of titanium and titanium carbide (titanium reacts with carbon to form titanium carbide). A dark gray area on one side of the interlayer represents plate-like titanium carbide, demonstrating sufficient reaction between the interlayer and graphite, resulting in a good metallurgical reaction. Another portion of the dark gray structure represents "finger-like" titanium carbide, primarily formed by carbon rapidly diffusing into the titanium structure through grain boundaries. This creates a "pinning" effect, facilitating crack deflection and enhancing interfacial strength. Surrounding the "finger-like" titanium carbide is primarily a [Mo, Ti] solid solution structure. During the high-temperature process, Mo atoms from the TZM alloy diffuse into the titanium, reacting to form a solid solution structure. Similarly, titanium atoms diffuse into the TZM alloy, thus achieving a metallurgical bond between the interlayer and the TZM alloy. The figure shows that there are no through-cracks or unwelded areas at the interface between the graphite and TZM, and there is no excessive solder loss, ensuring a good metallurgical bond at the interface.

[0026] Figure 2 This is the interface element surface scanning result of the TZM / graphite composite material obtained in Example 2. In the Mo element diagram, Mo is in pink. It can be seen that in addition to the TZM alloy side, Mo atoms are also present in the middle layer, forming a Mo-Ti solid solution area with Ti, overlapping with the green middle layer titanium. It can be seen that there is a green area inside the graphite on the left, which is mainly due to zirconium diffusing into the graphite through the graphite pores after melting. The red area is carbon. It can be seen that a part of the red area on the left is displayed in black, which is the zirconium filling area. Figure 3 The interface element content statistics of the TZM / graphite composite material obtained in Example 2 show that no other impurity elements are present at the TZM / Ti / graphite interface, indicating that the raw materials can be kept clean during the welding process, ensuring the metallurgical bonding of the joint.

[0027] Example 3 This embodiment discloses an SPS preparation method using titanium hydride powder for sintering connection with graphite. The difference from Example 1 is that the segmented heating process in step five is different, specifically the diffusion connection stage: axial pressure: when pressurized to the connection temperature at a pressurization rate of 0.2-0.5 MPa / min, the pressure is 30 MPa, the heating rate is 12°C / min, the connection temperature is 1590°C, and the holding time is 5 minutes.

[0028] Comparative Example 1 This comparative example provides a method for preparing SPS by sintering and connecting TZM and graphite using titanium hydride powder. The difference from Example 2 is that the segmented heating process in step five is different, specifically the diffusion connection stage: axial pressure: when pressurized to the connection temperature at a pressurization rate of 0.2-0.5 MPa / min, the pressure is 30 MPa, the heating rate is 12°C / min, the connection temperature is 1570°C, and the holding time is 5 minutes.

[0029] Comparative Example 2 This comparative example provides a method for preparing SPS by sintering and connecting TZM and graphite using titanium hydride powder. The difference from Example 2 is that the segmented heating process in step five is different, specifically the diffusion connection stage: the axial pressure at the connection temperature is 10 MPa, the heating rate is 12°C / min, the connection temperature is 1570°C, and the holding time is 10 min.

[0030] Comparative Example 3 This comparative example provides an SPS preparation method for sintering and connecting TZM and graphite using titanium hydride powder. The difference from Example 2 lies in step five: after wrapping a layer of carbon felt on the outside of the mold, it is placed in the furnace chamber of a spark plasma sintering furnace, and an axial pressure of 30 MPa is applied to the upper and lower pressure heads of the graphite. After vacuuming to 5 Pa, a DC pulse current is then passed to sinter and diffusion-bond the TZM and graphite dissimilar materials. The process is segmented heating: The first stage is the purification and degassing stage: The axial pressure is 30 MPa, the heating rate is 8°C / min, the degassing temperature is 900°C, and the holding time is 30 min; The second stage is the diffusion connection stage: The axial pressure at the connection temperature is still 30 MPa, the heating rate is 12 ° C / min, the connection temperature is 1570 ° C, and the holding time is 10 min; The third stage is the cooling stage: The cooling method is loaded cooling with a cooling rate of 8°C / min to 1000°C and 12°C / min to 500°C, and then furnace cooling to obtain TZM / graphite composite material.

[0031] First, the TZM / graphite composite materials obtained in Examples 1-3 and Comparative Examples 1-3 were tested for room temperature interfacial shear strength using an IBTC-5000 in-situ tensile and compressive testing system (Kaier Measurement & Control, Tianjin). The loading rate was 0.5 mm / min. During the test, the force was applied to the middle interface with the graphite part on the outside. Three sets of repetitions were performed, and the results were averaged. The data statistics are shown in Table 1.

[0032] Table 1. Room temperature interfacial shear strength of TZM / graphite composites ; From Table 1, Figure 4 It can be seen from the figure that the average room temperature interface shear strength of the TZM / graphite composite material obtained by the SPS preparation method for connecting TZM and graphite by sintering with titanium hydride provided in the embodiment can reach up to 56.33 MPa.

[0033] The holding time in Comparative Example 1 is shorter than that in Example 2. The results show that the holding time has an impact on the interfacial strength of the TZM / graphite composite material. Comparative Examples 2-3, when compared with Example 2, maintain the compressive strengths at 10 MPa and 30 MPa, respectively, during the preparation of the TZM / graphite composite material. The resulting connectors exhibit significantly lower interfacial shear strengths than Example 2. Furthermore, when the compressive strengths during the preparation of the TZM / graphite composite material are maintained at 30 MPa, the resulting connectors exhibit lower interfacial shear strengths than Example 2. Dynamic adjustment of the compressive strength during the preparation process contributes to improved interfacial shear strength of the connectors.

[0034] Secondly, the TZM / graphite composite materials obtained in Example 2 and Comparative Examples 1-3 were subjected to thermal shock tests to evaluate the structural stability and durability of the composite materials under rapid temperature changes. The specific steps were as follows: placing the TZM / graphite composite materials in an intermediate frequency furnace, evacuating to 10 -2 Pa, heated to 1000 °C, kept warm for 20 min, stopped heating, and cooled to room temperature in the furnace. After repeated heating 10 times, the room temperature interface shear strength of the TZM / graphite composite material was tested using the IBTC-5000 in-situ tension and compression testing system (Kai'er Measurement & Control, Tianjin). The room temperature interface shear strength of the TZM / graphite composite material before and after the test was statistically analyzed. Three groups of repetitions were performed, and the strength loss rate was calculated. The results were averaged and shown in Table 2.

[0035] Table 2. Thermal shock test results ; As can be seen from Table 2, the strength loss of the TZM / graphite composite material obtained in Example 2 after the thermal shock test is lower than that of the TZM / graphite composite material obtained in Comparative Examples 1-2, and the strength loss rate is between 1.8-3.6%. The TZM / graphite composite material obtained in Example 2 has a strong resistance to thermal stress damage. The average strength loss rate of Example 2 and Comparative Examples 1-2 is shown in FIG. Figure 5 shown.

[0036] Finally, in order to compare the technical effects of the SPS preparation method for sintering and connecting TZM and graphite using titanium hydride powder provided by the present invention, the optimal embodiments of the prior art, such as the SPS pressureless brazing method of a TZM alloy block and a graphite block disclosed in the authorization publication number CN113770467B (referred to as prior art A) and the SPS diffusion welding method of TZM and graphite dissimilar materials disclosed in the authorization publication number CN109048030B (referred to as prior art B), are compared with the optimal embodiments of the present invention, as shown in Table 3.

[0037] Table 3. Comparison between the present invention and the prior art ; As shown in Table 3, using titanium hydride powder as the intermediate solder, the welding temperature for connecting TZM and graphite is 1570°C and the holding time is 10 minutes. Compared with the pressureless brazing method of prior art A, the temperature is reduced by 60°C, and the applicable pressure is 30 MPa, which can meet other pressure welding scenarios. Furthermore, for the same TZM alloy material, higher temperatures lead to faster grain boundary migration and more pronounced grain growth. Compared with the diffusion welding method of prior art B, the temperature is increased, but the high temperature time is shorter, which can reduce the impact on the performance of the TZM sheet. Furthermore, the interfacial shear strength of the TZM / graphite composite material obtained by the present invention is significantly improved compared to the TZM / graphite composite material obtained by prior art B.

[0038] The above-described embodiments merely illustrate several implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, and all such variations and improvements fall within the scope of protection of the present invention.

Claims

1. A method for preparing SPS by sintering and connecting TZM and graphite using titanium hydride powder, characterized in that: The following steps are involved: Step 1: Grind, ultrasonically clean, dry with nitrogen, and heat and keep warm under vacuum conditions on the surfaces to be welded of TZM and graphite; Step 2: heating the titanium hydride powder under vacuum conditions and keeping the temperature constant; Step 3: Place the processed TZM, titanium hydride powder and graphite in the graphite mold from bottom to top, and press the upper and lower ends of the graphite mold with a graphite press head; Step 4: Place the graphite mold assembled in step 3 in the furnace of the spark plasma sintering system, apply axial pressure, evacuate, and then pass a DC pulse current to sinter and diffuse the TZM and graphite.

2. The SPS preparation method for sintering TZM and graphite using titanium hydride powder according to claim 1, characterized in that: In step 1, the surface to be welded of the TZM alloy block was mechanically polished with 400, 1000 and 2000 grit sandpaper in sequence, and then ultrasonically cleaned with anhydrous ethanol, alkali solution with a pH of 7-7.5 and pure water in sequence, and then dehydrated with anhydrous ethanol and dried with nitrogen. The treated TZM alloy block was placed in a high-temperature vacuum heat treatment furnace and vacuumed to 5×10 -3 Pa, and heat to 1400℃ and keep warm for 30min.

3. The SPS preparation method for sintering TZM and graphite using titanium hydride powder according to claim 1, characterized in that: In step 1, the graphite is first ultrasonically cleaned with pure water and dried with nitrogen, and then the treated graphite is placed in a vacuum oven, evacuated, heated to 100°C, and kept warm for 5 hours.

4. The SPS preparation method for sintering TZM and graphite using titanium hydride powder according to claim 1, characterized in that: In step 2, the titanium hydride powder has a Fisher particle size of 1-30 μm and a purity of ≥99.5%.

5. The SPS preparation method for sintering TZM and graphite using titanium hydride powder according to claim 1, characterized in that: In step 2, the titanium hydride powder is placed in a vacuum oven, evacuated, and then heated to 70° C. for 1 hour.

6. The SPS preparation method for sintering TZM and graphite using titanium hydride powder according to claim 1, characterized in that: In step 4, an axial pressure of 10 MPa is applied to the upper and lower pressure heads of the graphite mold, and the pressure is evacuated to 5 Pa.

7. The SPS preparation method for sintering TZM and graphite using titanium hydride powder according to claim 1, characterized in that: In step 4, the sintering and diffusion bonding process of TZM and graphite dissimilar materials is segmented heating, and the specific settings are as follows: The first stage is the purification and degassing stage: The axial pressure is 10 MPa; the heating rate is 5-10°C / min, the degassing temperature is 800-1000°C, and the holding time is 30-60 min; The second stage is the diffusion connection stage: The connection temperature is 1500-1600℃, the heating rate is 10-15℃ / min, the holding time is 5-20min, and the axial pressure at the connection temperature is 30MPa; The third stage is the cooling stage: The cooling method is load cooling, first cooling to 1000℃ at a cooling rate of 5-10℃ / min, then cooling to 500℃ at a cooling rate of 10-15℃ / min, and finally cooling with the furnace.

8. The SPS preparation method for sintering TZM and graphite using titanium hydride powder according to claim 7, characterized in that: The degassing temperature is 900°C and the holding time is 30 minutes.

9. A TZM / graphite composite material prepared by the SPS preparation method according to any one of claims 1 to 8.

10. The TZM / graphite composite material according to claim 9, characterized in that: The room temperature interface shear strength of the TZM / graphite composite material is ≥50 MPa.

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