A sintering method for connecting TZM and graphite by SPS using titanium hydride powder and application thereof

Abstract

The application discloses a TZM and graphite sintering connection SPS preparation method using titanium hydride powder and application in the field of TZM and graphite dissimilar material connection, and particularly relates to using titanium hydride powder as an intermediate layer material, sintering and diffusion connecting TZM and graphite dissimilar materials through SPS technology, so as to obtain TZM / graphite composite materials. The method has the following advantages: using titanium hydride powder as an intermediate layer material, compared with the existing titanium powder or titanium foil, it is green and environmentally friendly, the composition is low, and the titanium hydride powder releases hydrogen and generates elemental titanium in the 400-800 DEG C interval, can remove the oxide layer of the base material while reducing the oxidation of titanium, promote the mutual diffusion and solid solution of interface Mo and Ti atoms, and the reaction with the graphite side, form a good metallurgical bonding interface, obtain TZM / graphite composite materials without crack defects, high interface bonding strength and good durability.

Description

Technical Field

[0001] This invention relates to the field of TZM / graphite dissimilar material bonding, specifically to a method for preparing SPS using titanium hydride powder to sinter and bond TZM and graphite, and its application. Background Technology

[0002] TZM alloys are a class of high-temperature molybdenum alloys with added trace amounts of elements such as Ti, Zr, and C, forming solid solutions such as Mo-Ti and Mo-Zr for reinforcement, and second-phase dispersion reinforcement 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 the second phase can significantly improve the strength and plasticity of TZM alloys by suppressing dislocation movement. TZM alloys possess excellent properties such as high melting point, low coefficient of thermal expansion, low creep rate, high thermal conductivity, and electrical conductivity, and are widely used in materials for reflector screens in nuclear fusion equipment, materials for electro-vacuum components, and matrix materials for X-ray tube target disks. Graphite, a low atomic weight material, has characteristics such as high melting point, low density, and strong heat dissipation capacity. Combining TZM alloys and graphite into novel composite materials has attracted widespread attention. This combination ensures strength, heat dissipation, and heat storage performance while significantly reducing the weight of the workpiece within the same volume, making it ideal for use in high-temperature and high-speed rotation conditions, such as the anode target disk components inside CT X-ray tubes.

[0003] Since TZM alloy and graphite are heterogeneous materials, the main joining methods currently used include high-temperature vacuum brazing, vacuum diffusion welding, and SPS diffusion welding. For example, patent CN102240836A discloses a vacuum brazing method for molybdenum and graphite, which uses NiCoPaTi foil as a filler metal to perform vacuum brazing on molybdenum and graphite, and obtains a room temperature interfacial shear strength of up to 16 MPa. For example, patent CN108161156A discloses a vacuum brazing method for molybdenum alloy and graphite, which uses TiCrTa foil to vacuum braze the molybdenum alloy and graphite, with a maximum room temperature shear strength of 21 MPa at the interface. Another example is patent CN111014869A, which discloses a vacuum welding method for molybdenum-based graphite, which discloses the preparation of porous TZM, and then the use of titanium powder or zirconium powder to sinter the porous TZM and graphite together in a vacuum hot press furnace, with a maximum room temperature strength of 21 MPa at the interface. The above brazing processes are relatively long and the strength is not high. For example, patent CN113770467A discloses an SPS pressureless brazing method for TZM alloy and graphite, which uses titanium foil to perform SPS pressureless brazing on TZM and graphite, achieving a room temperature interfacial shear strength of 55 MPa. However, under pressure, it is prone to excessive solder loss. Another example is patent CN109048030B, which discloses an SPS diffusion welding method for dissimilar materials TZM and graphite, specifically using titanium foil to perform SPS diffusion welding on TZM alloy and graphite. The highest room temperature interfacial shear strength is 49 MPa, but due to the long welding time, it is prone to deterioration of the base material properties.

[0004] Therefore, to address the above problems, this invention employs SPS technology to sinter and bond TZM alloy / titanium hydride powder / graphite, ensuring that a composite material with excellent interfacial properties can be obtained under certain pressure conditions. Summary of the Invention

[0005] This invention addresses the existing welding system of TZM alloy and graphite heteromaterials by providing a method for preparing SPS using titanium hydride powder to sinter and connect TZM and graphite, as well as its application.

[0006] The present invention achieves the above objectives through the following technical solutions:

[0007] As a first aspect of the present invention, a method for preparing SPS using titanium hydride powder sintering to connect TZM and graphite is provided, comprising the following steps:

[0008] Step 1: Grind, ultrasonically clean, and dry the surfaces of TZM and graphite to be welded with nitrogen, and heat and keep warm under vacuum conditions;

[0009] Step 2: Heat and maintain the temperature of titanium hydride powder under vacuum conditions;

[0010] Step 3: Place the processed TZM, titanium hydride powder and graphite into the graphite mold from bottom to top in sequence, and press the upper and lower ends of the graphite mold together with the graphite pressure head.

[0011] Step 4: Place the graphite mold assembled in Step 3 into 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 together.

[0012] As a further optimization of the present invention, in step one, the surface of the TZM alloy block to be welded is first mechanically polished with 400, 1000, and 2000 grit sandpaper in sequence to remove surface impurities and oxide layers. Then, it is ultrasonically cleaned with anhydrous ethanol, an alkaline solution with a pH of 7-7.5, and pure water in sequence. Next, it is dehydrated with anhydrous ethanol, dried with nitrogen, and then placed in a high-temperature vacuum heat treatment furnace, where a vacuum of 5×10⁻⁶ is applied. -3 The temperature is below Pa, and then heated to 1400℃ and held for 30 minutes to further remove impurities and oxide layers from the TZM surface.

[0013] As a further optimization of the present invention, in step one, the graphite is first ultrasonically cleaned with pure water and dried with nitrogen, and then the treated graphite is placed in a vacuum oven, vacuumed, heated to 100°C, and kept at that temperature for 5 hours.

[0014] As a further optimization of the present invention, in step two, titanium hydride powder is placed in a vacuum oven, vacuumed, heated to 70°C, and kept at that temperature for 1 hour.

[0015] As a further optimization of the present invention, in step two, 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.

[0016] As a further optimization of the present invention, in step four, an axial pressure of 10 MPa is applied to the upper and lower pressure heads of the graphite mold, and a vacuum is drawn to 5 Pa.

[0017] As a further optimization of the present invention, in step four, the sintering and diffusion bonding process of TZM and graphite dissimilar materials is carried out by segmented heating, specifically configured as follows:

[0018] The first stage is the purification and degassing stage:

[0019] The axial pressure is 10 MPa; the heating rate is 5-10℃ / min; the degassing temperature is 800-1000℃; and the holding time is 30-60 min.

[0020] The second stage is the diffusion connection stage:

[0021] Axial pressure: When pressurized to the connection temperature at a pressurization rate of 0.2-0.5MPa / min, the pressure is 30MPa, and the heating rate is 10-15℃ / min;

[0022] The connection temperature is 1500-1600℃, and the heat preservation time is 5-20 minutes.

[0023] The third stage is the cooling stage:

[0024] The cooling method is under 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.

[0025] As a further optimization of the present invention, the temperature and holding time of the purification and degassing stage are related to the purity of titanium hydride powder and graphite raw materials and the amount of gas absorbed. The degassing platform temperature and holding time are determined according to the vacuum degree of the equipment. The degassing temperature is preferably 900℃ and the holding time is preferably 30min.

[0026] As a second aspect of the present invention, a TZM / graphite composite material prepared by the SPS preparation method as described in any one of the above claims is also provided.

[0027] As a further optimization of the present invention, the room temperature interfacial shear strength of the TZM / graphite composite material is ≥50MPa.

[0028] The beneficial effects of this invention are as follows:

[0029] (1) This invention uses titanium hydride powder as an intermediate layer material for the sintering 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 400-800℃ range. This can remove the oxide layer of the base material while reducing the oxidation of titanium, promoting the interdiffusion solid solution of Mo and Ti atoms at the interface, as well as the reaction with the graphite side, forming a good metallurgical bonding interface. Compared with the titanium foil used in the prior art, this invention can reduce the excessive extrusion of the interface due to the deformation and softening of the titanium foil during sintering heating and pressurization, which leads to insufficient solder in the interface layer. It also reduces the acid washing process required for conventional titanium foil use, making it green, environmentally friendly, and low in cost.

[0030] (2) The present invention uses SPS sintering technology to sinter and diffuse the dissimilar materials TZM and graphite. Since the powder has a large specific surface area and a large contact area with TZM and graphite, SPS technology has an activation effect on the powder surface, which can complete the densification of the intermediate layer powder and the atomic diffusion and reaction process between the interfaces in a short time, thus obtaining a TZM / graphite composite material with no crack defects, high interfacial bonding strength and good durability. Attached Figure Description

[0031] Figure 1 Here is an SEM image of the interface of the TZM / graphite composite material prepared in Example 2;

[0032] Figure 2 The interfacial element surface scan results are shown for the TZM / graphite composite material prepared in Example 2.

[0033] Figure 3 Statistics on the interfacial element content of the TZM / graphite composite material prepared in Example 2;

[0034] Figure 4 The test results show the room temperature interfacial shear strength of the TZM / graphite composite material.

[0035] Figure 5 The results are from the thermal shock test of the TZM / graphite composite material. Detailed Implementation

[0036] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0037] The spark plasma sintering furnace used in the following examples is the LABOX-350 series spark plasma sintering system manufactured by Sinter Land Corporation of Japan. Its current type is DC pulse current and the pulse sequence is 40:7.

[0038] The TZM alloy used in the following examples is in the forged state, the graphite is high-strength graphite, and the composition of the TZM alloy is 0.4-0.6 wt% Ti, 0.07-0.12 wt% Zr and 0.01-0.04 wt% C, with the remainder being Mo (excluding impurities); the carbon content of the graphite is greater than 99.99%.

[0039] Example 1

[0040] This embodiment discloses a method for preparing SPS (Sintered Particulate Polyacrylamide) by sintering titanium hydride powder to connect TZM alloy blocks and graphite. The specific steps are as follows:

[0041] Step 1: First, mechanically grind the welding surface of the Φ20mm×2mm TZM alloy block using 400, 1000, and 2000 grit sandpaper in sequence. Then, ultrasonically clean it sequentially using anhydrous ethanol, an alkaline solution with a pH of 7-7.5 (Lanfei aluminum alloy cleaning solution), and pure water. Next, dehydrate it with anhydrous ethanol, dry it with nitrogen, and then place the treated TZM alloy block into a high-temperature vacuum heat treatment furnace, where a vacuum of 5×10⁻⁶ is applied. -3The material is heated to 1400℃ and held for 30 minutes below Pa, then cooled to room temperature in the furnace before being removed.

[0042] Step 2: Clean the Φ20mm×2mm graphite block with pure water using ultrasonic cleaning, dry it with nitrogen, put it in a vacuum oven, evacuate it to 50Pa, heat it to 100℃, and keep it at that temperature for 5 hours.

[0043] Step 3: Weigh 0.5g of titanium hydride powder (Fairwood particle size 1-4μm, purity ≥99.5%) and place it in a vacuum oven. After vacuuming, heat to 70℃ at 50Pa and keep warm for 1 hour.

[0044] Step 4: Place the prepared TZM alloy block, titanium hydride powder and graphite into the graphite mold from bottom to top. The upper and lower ends of the graphite mold are pressed together by the graphite pressure head to obtain a graphite mold containing the parts to be welded.

[0045] Step 5: After wrapping the outside of the mold with a layer of carbon felt, place it in the furnace chamber of the spark plasma sintering furnace. Apply an axial pressure of 10 MPa to the upper and lower pressure heads of the graphite, evacuate to 5 Pa, and then pass a DC pulse current to sinter and diffuse the dissimilar materials TZM and graphite. The process involves segmented heating.

[0046] The first stage is the purification and degassing stage:

[0047] The axial pressure is 10 MPa, the heating rate is 8℃ / min, the degassing temperature is 900℃, and the holding time is 30 min.

[0048] The second stage is the diffusion connection stage:

[0049] Axial pressure: When pressurized to the connection temperature at a rate of 0.2-0.5 MPa / min, the pressure is 30 MPa; the heating rate is 12℃ / min, the connection temperature is 1550℃, and the holding time is 20 min.

[0050] The third stage is the cooling stage:

[0051] The cooling method was under load cooling at a rate of 8℃ / min, cooling to 1000℃, then 12℃ / min, cooling to 500℃, followed by furnace cooling to obtain TZM / graphite composite material.

[0052] Example 2

[0053] This embodiment discloses a method for preparing SPS (Sintered Polymerized Particles) by sintering titanium hydride powder to connect TZM alloy blocks and graphite. The difference from Embodiment 1 lies in the segmented heating process in step five, which is specifically a diffusion bonding stage:

[0054] Axial pressure: When pressurized to the connection temperature at a rate of 0.2-0.5 MPa / min, the pressure is 30 MPa, the heating rate is 12℃ / min, the connection temperature is 1570℃, and the holding time is 10 min.

[0055] Figure 1 Here is a SEM image of the interface of the TZM / graphite composite material obtained in Example 2. Figure 1 In the image, the black area represents graphite with a small amount of titanium inside. This is due to the island-like titanium and titanium carbide structures formed by the diffusion of molten titanium through the graphite pores during the welding process (titanium reacts with carbon to form titanium carbide). One side of the intermediate layer is dark gray, resembling a plate-like structure of titanium carbide, indicating a sufficient reaction between the intermediate layer and graphite, resulting in a good metallurgical reaction. Another portion of the dark gray structure is a finger-like titanium carbide structure, mainly formed by carbon diffusing rapidly through grain boundaries into the titanium microstructure, acting as a "pinning" effect, which is beneficial for crack deflection and improves interface strength. Surrounding the "finger-like" titanium carbide is primarily a [Mo, Ti] solid solution structure. During high-temperature processing, Mo atoms in the TZM alloy diffuse into the titanium, reacting to form a solid solution structure. Similarly, titanium atoms also diffuse into the TZM alloy, thus achieving a metallurgical bond between the intermediate layer and the TZM alloy interface. As can be seen from the image, there are no through cracks or unbonded areas at the graphite-TZM interface, and no excessive loss of solder, ensuring a good metallurgical bond at the interface.

[0056] Figure 2 The interface element surface scan results of the TZM / graphite composite material obtained in Example 2 are shown. In the Mo element diagram, Mo is in pink. It can be seen that in addition to the TZM alloy side, Mo atoms also exist in the intermediate layer, forming a Mo-Ti solid solution region with Ti, which overlaps with the green intermediate titanium layer. It can be seen that there is a green region inside the graphite on the left, which is mainly the diffusion of zirconium into the graphite interior through the graphite pores after melting. The red region is carbon. It can be seen that a part of the red region on the left is black, which is the zirconium-filled region. Figure 3 The statistical analysis of the interfacial element content of the TZM / graphite composite material obtained in Example 2 shows that there are no other impurity elements present at the TZM / Ti / graphite interface, indicating that the cleanliness of the raw materials can be maintained during the welding process, ensuring the metallurgical bonding of the joint.

[0057] Example 3

[0058] This embodiment discloses a method for preparing SPS by sintering titanium hydride powder with graphite. The difference from Embodiment 1 is that the segmented heating process in step five is different. Specifically, in the diffusion bonding stage: axial pressure: when pressurized to the bonding temperature at a pressurization rate of 0.2-0.5 MPa / min, the pressure is 30 MPa, the heating rate is 12℃ / min, the bonding temperature is 1590℃, and the holding time is 5 min.

[0059] Comparative Example 1

[0060] This comparative example provides a method for preparing SPS using titanium hydride powder to sinter and bond TZM and graphite. The difference between this method and Example 2 is the segmented heating process in step five. Specifically, in the diffusion bonding stage: axial pressure: when pressurized to the bonding temperature at a rate of 0.2-0.5 MPa / min, the pressure is 30 MPa, the heating rate is 12℃ / min, the bonding temperature is 1570℃, and the holding time is 5 min.

[0061] Comparative Example 2

[0062] This comparative example provides a method for preparing SPS using titanium hydride powder to sinter and connect TZM and graphite. The difference between this method and Example 2 is that the segmented heating process in step five is different. Specifically, in 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.

[0063] Comparative Example 3

[0064] This comparative example provides a method for preparing SPS (Spectrophotometric Polymerization) by sintering titanium hydride powder to bond TZM (Titanium Zinc Hydrogenation Mold) and graphite. The difference from Example 2 lies in step five: after wrapping the outside of the mold with a layer of carbon felt, it is placed in the furnace chamber of a spark plasma sintering furnace. An axial pressure of 30 MPa is applied to the upper and lower pressure heads of the graphite. After evacuating to 5 Pa, a DC pulse current is then applied to sinter and diffuse the dissimilar materials TZM and graphite. The process involves segmented heating.

[0065] The first stage is the purification and degassing stage:

[0066] The axial pressure is 30 MPa, the heating rate is 8℃ / min, the degassing temperature is 900℃, and the holding time is 30 min.

[0067] The second stage is the diffusion connection stage:

[0068] The axial pressure at the connection temperature is still 30MPa, the heating rate is 12℃ / min, the connection temperature is 1570℃, and the holding time is 10min.

[0069] The third stage is the cooling stage:

[0070] The cooling method was under load cooling at a rate of 8℃ / min, cooling to 1000℃, then 12℃ / min, cooling to 500℃, followed by furnace cooling to obtain TZM / graphite composite material.

[0071] First, the room temperature interfacial shear strength of the TZM / graphite composite materials obtained in Examples 1-3 and Comparative Examples 1-3 was tested using an IBTC-5000 in-situ tensile and compressive mechanical testing system (Kail Measurement and Control, Tianjin). The loading rate was 0.5 mm / min. During the test, the stress location was the middle interface with the graphite part on the outside. Three sets of tests were repeated, and the average value of the results was taken. The data statistics are shown in Table 1.

[0072] Table 1. Room temperature interfacial shear strength of TZM / graphite composites

[0073] ;

[0074] From Table 1, Figure 4 As can be seen from the examples, the TZM / graphite composite material obtained by the SPS preparation method of sintering TZM and graphite with titanium hydride provided in the examples can reach an average room temperature interfacial shear strength of up to 56.33 MPa.

[0075] The heat preservation time in Comparative Example 1 was shorter than that in Example 2. The results show that the heat preservation time affects the interfacial strength of the TZM / graphite composite material. Comparative Examples 2-3, compared to Example 2, maintained a constant compressive strength of 10 MPa and 30 MPa during the preparation of the TZM / graphite composite material, respectively. The resulting interfacial shear strength of the connectors was significantly lower than that of Example 2. Furthermore, maintaining a constant compressive strength of 30 MPa during the preparation of the TZM / graphite composite material also resulted in lower interfacial shear strength of the connectors compared to Example 2. Dynamic adjustment of the compressive strength during the preparation process helps to improve the interfacial shear strength of the connectors.

[0076] Secondly, thermal shock tests were conducted on the TZM / graphite composite materials obtained in Example 2 and Comparative Examples 1-3 to evaluate the structural stability and durability of the composite materials under rapid temperature change environments. Specifically, the TZM / graphite composite materials were placed in an intermediate frequency furnace and evacuated to 10°C. -2 Below Pa, the temperature was raised to 1000℃ and held for 20 minutes. The heating was then stopped, and the temperature was allowed to drop to room temperature in the furnace. This process was repeated 10 times. The room temperature interfacial shear strength of the TZM / graphite composite material was then tested using an IBTC-5000 in-situ tensile and compressive mechanical testing system (Kail Measurement and Control, Tianjin). The room temperature interfacial shear strength of the TZM / graphite composite material before and after the test was statistically analyzed. Three sets of tests were performed, and the strength loss rate was calculated. The average value of the results was taken. The results are shown in Table 2.

[0077] Table 2. Thermal shock test results

[0078] ;

[0079] As shown in Table 2, the strength loss of the TZM / graphite composite material obtained in Example 2 after thermal shock testing is lower than that of the TZM / graphite composite materials obtained in Comparative Examples 1-2, with a strength loss rate between 1.8% and 3.6%. The TZM / graphite composite material obtained in Example 2 has strong resistance to thermal stress damage. The average strength loss rate of Example 2 and Comparative Examples 1-2 is statistically shown in Table 2. Figure 5 As shown.

[0080] Finally, to compare the technical effects of the SPS preparation method for sintering TZM and graphite using titanium hydride powder provided by the present invention, the optimal embodiments of the present invention are compared with those of the prior art, such as the SPS pressureless brazing method for TZM alloy blocks and graphite blocks disclosed in patent publication number CN113770467B (denoted as prior art A) and the SPS diffusion welding method for TZM and graphite dissimilar materials disclosed in patent publication number CN109048030B (denoted as prior art B), as shown in Table 3.

[0081] Table 3. Comparison between the present invention and the prior art

[0082] ;

[0083] As shown in Table 3, using titanium hydride powder as the intermediate layer solder, the welding temperature for connecting TZM and graphite is 1570℃, and the holding time is 10 min. Compared with the pressureless brazing of prior art A, the temperature is reduced by 60℃, and a pressure of 30 MPa can be applied, which can meet other pressure welding scenarios. For the same TZM alloy material, the higher the temperature, the faster the grain boundary migration and the more obvious the grain growth. Compared with the diffusion welding of prior art B, the temperature is increased, but the high-temperature time is shorter, which can reduce the impact on the properties of TZM sheet. Moreover, the interfacial shear strength of the TZM / graphite composite material obtained by this invention is significantly improved compared with the TZM / graphite composite material obtained by prior art B.

[0084] The embodiments described above are merely examples of several implementations of the present invention, and 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 those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A method for preparing SPS using titanium hydride powder sintering to bond TZM and graphite, characterized in that, Includes the following steps: Step 1: Grind, ultrasonically clean, and dry the surfaces of TZM and graphite to be welded with nitrogen, and heat and keep warm under vacuum conditions; Step 2: Heat and maintain the temperature of titanium hydride powder under vacuum conditions; Step 3: Place the processed TZM, titanium hydride powder and graphite into the graphite mold from bottom to top in sequence, and press the upper and lower ends of the graphite mold together with the graphite pressure head. Step 4: Place the graphite mold assembled in Step 3 into 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 together.

2. The method for preparing SPS using titanium hydride powder sintering to connect TZM and graphite according to claim 1, characterized in that, In step one, the surfaces of the TZM alloy block to be welded are first mechanically polished with 400, 1000, and 2000 grit sandpaper in sequence. Then, they are ultrasonically cleaned with anhydrous ethanol, an alkaline solution with a pH of 7-7.5, and pure water in sequence. After dehydration with anhydrous ethanol and drying with nitrogen, the treated TZM alloy block is placed in a high-temperature vacuum heat treatment furnace and evacuated to a vacuum of 5×10⁻⁶. -3 The temperature is below Pa, and then heated to 1400℃ and held for 30 minutes.

3. The method for preparing SPS using titanium hydride powder sintering to connect TZM and graphite according to claim 1, characterized in that, In step one, the graphite is first ultrasonically cleaned with pure water and dried with nitrogen. Then, the treated graphite is placed in a vacuum oven, vacuumed, heated to 100°C, and kept at that temperature for 5 hours.

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

5. The method for preparing SPS using titanium hydride powder sintering to connect TZM and graphite according to claim 1, characterized in that, In step two, titanium hydride powder is placed in a vacuum oven, evacuated, heated to 70°C, and kept at that temperature for 1 hour.

6. The method for preparing SPS using titanium hydride powder sintering to connect TZM and graphite according to claim 1, characterized in that, In step four, an axial pressure of 10 MPa is applied to the upper and lower pressure heads of the graphite mold, and a vacuum is drawn to 5 Pa.

7. The method for preparing SPS using titanium hydride powder sintering to connect TZM and graphite according to claim 1, characterized in that, In step four, the sintering and diffusion bonding process between TZM and graphite dissimilar materials is carried out using segmented heating, with the specific settings as follows: The first stage is the purification and degassing stage: The axial pressure is 10 MPa; the heating rate is 5-10℃ / min; the degassing temperature is 800-1000℃; 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 under 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 method for preparing SPS using titanium hydride powder sintering to connect TZM and graphite according to claim 7, characterized in that, The degassing temperature is 900℃, 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 1-8.

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

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