A duplex-strengthening rare earth-containing Ti-based cermet, a preparation method and application thereof

Abstract

The application belongs to the technical field of cermet composite materials, and provides a dual-phase reinforced rare earth-containing Ti-based cermet, which comprises the following components in mass percentage: 60-70% of a multi-element Ti-based solid solution ceramic phase, 15-25% of a carbide phase, 12-23% of a metal binder phase, and 0.1-0.8% of a rare earth oxide phase; the metal binder phase is a dual-phase structure in which an amorphous phase and a crystalline phase coexist. The application controls the hard phase composition and the binder phase structure in a synergistic manner, forms the dual-phase structure in which the amorphous phase and the crystalline phase coexist in the binder phase, thereby improving the interface bonding state between the ceramic phase and the metal binder phase, reducing the interface stress concentration, and improving the fracture toughness, strength and wear resistance of the material.

Description

Technical Field

[0001] This invention relates to the field of metal-ceramic composite materials technology, and in particular to a dual-phase reinforced rare-earth Ti-based metal-ceramic, its preparation method, and its application. Background Technology

[0002] TiC and Ti(C,N)-based cermets are typically produced using powder metallurgy. TiC, TiN, or Ti(C,N) serves as the ceramic matrix phase, with carbides such as Mo2C, WC, TaC, NbC, and Cr3C2, and metal binders such as Co, Ni, or Fe added. The mixture is then mixed, molded, and sintered to create a cermet composite material. These materials exhibit high high-temperature hardness, wear resistance, oxidation resistance, thermal stability, and a low coefficient of friction. Furthermore, their density is significantly lower than that of traditional WC cemented carbide (WC cemented carbide typically has a density of 12-15 g / cm³). 3 The density of TiC and Ti(C,N)-based cermets is generally 5.5~7.5 g / cm³. 3 Therefore, this type of material has wide applications in metal cutting, wear-resistant parts, and other fields. However, its fracture toughness, impact toughness, and bending strength are relatively low, and it is prone to brittle failure under high impact loads or intermittent cutting conditions, thus limiting its application range.

[0003] In existing technologies, to improve the mechanical properties of TiC or Ti(C,N)-based cermets, carbides such as Mo2C, WC, TaC, and NbC are typically introduced. During sintering, these carbides undergo a dissolution-precipitation mechanism to form a (Ti,Me)(C,N) solid solution phase (where Me represents elements such as Mo, W, Ta, and Nb), creating a typical "core-ring" structure around the ceramic particles. The core consists of incompletely dissolved TiC or Ti(C,N) particles, while the ring phase is the (Ti,Me)C or (Ti,Me)(C,N) solid solution phase formed by the reaction of the TiC or Ti(C,N) ceramic phase with the carbides. This structure reduces the interfacial energy between the ceramic and metal binder phases, decreasing the contact angle between the molten metal and the ceramic phase, improving the wetting properties between the two phases, promoting the dispersed distribution of the carbide phase, and facilitating the formation of a continuous and uniform thin film of the metal binder phase to coat the hard particles. Simultaneously, it avoids the coalescence and growth of ceramic particles due to direct contact, refining the grain size and thus improving the overall performance of the cermet.

[0004] However, under traditional preparation processes, not all Ti(C,N) powder particles can fully undergo a solid solution reaction with carbide powders such as Mo2C to form a complete and uniform "core-ring" structure. Some Ti(C,N) powder will still directly or partially contact the metal binder phases such as Co and Ni, leading to a decrease in the interfacial bonding strength between the ceramic and metal phases, and generating significant lattice mismatch and interfacial stress in localized areas. Furthermore, carbides such as Mo2C, WC, TaC, and NbC, in addition to participating in the formation of (Ti,Me)(C,N) solid solutions, may also form intermetallic compounds with the metal binder phases, making it difficult to precisely control the composition of the solid solution phases. Excessive metal carbides combining with metal binders such as Co and Ni can actually reduce the bonding strength of the binder phase in the alloy, thus reducing the strength and toughness of the cermet.

[0005] On the other hand, amorphous alloys, also known as metallic glasses, possess a metastable structure characterized by short-range order and long-range disorder. In the solid state, their atoms exhibit a topologically disordered arrangement in three-dimensional space, and this state remains relatively stable within a certain temperature range. Compared to crystalline materials, amorphous alloys lack defects such as dislocations and grain boundaries, thus exhibiting superior mechanical properties, such as high hardness, high strength, high electrical resistance, corrosion resistance, and wear resistance. If a certain proportion of amorphous structures can be formed in the metallic binder phase of TiC and Ti(C,N)-based cermets, it is expected to further improve the hardness, strength, and wear resistance of the binder phase, thereby improving the overall comprehensive performance of the cermet and the overall material properties. However, traditional methods for preparing amorphous alloys mainly include flux water quenching, metal mold casting, electric arc melting copper mold suction casting, pressure casting, and water quenching. Although these methods can prepare amorphous alloys, due to the limitation of the critical cooling rate, it is difficult to obtain bulk amorphous alloys with complex three-dimensional dimensions or shapes when preparing bulk amorphous alloys of a certain size. Meanwhile, the ability to form amorphous structures is also closely related to factors such as alloy composition, atomic size difference, and heat of mixing. Therefore, achieving stable and controllable amorphous structures in cermet systems remains quite challenging.

[0006] Furthermore, rare earth elements can improve the interfacial structure and regulate the morphology of the binder phase in metal-ceramic systems. For example, rare earth elements have a strong affinity for oxygen, which can purify the metal binder phase and suppress heterogeneous nucleation during liquid-phase sintering. At the same time, by changing the atomic size distribution and interfacial energy state of alloying elements, they can reduce the driving force for crystal growth, thereby improving the overall mechanical properties of the material.

[0007] Therefore, how to further improve the flexural strength, fracture toughness and impact toughness of TiC and Ti(C,N)-based cermets by controlling the hard phase structure and binder phase structure while ensuring the hardness of TiC and Ti(C,N)-based cermets remains a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0008] The purpose of this invention is to address the problems of uneven hard phase structure, difficulty in controlling the binder phase structure, and insufficient impact / fracture toughness in existing TiC and Ti(C,N) based cermets, and to provide a dual-phase reinforced rare earth Ti-based cermet, its preparation method, and its application.

[0009] This invention optimizes the microstructure of materials by synergistically controlling the microstructure of the hard phase and the composition of the binder phase, thereby improving the comprehensive mechanical properties of cermets.

[0010] This invention employs a Ti-based multi-element solid solution ceramic phase containing Mo as the hard phase, enabling it to form a relatively uniform, weak "core-ring" hard phase structure during sintering. This improves the interfacial coherence between the ceramic phase and the metal binder phase, thereby reducing stress concentration at the "core-ring" structure interface. Simultaneously, by introducing rare earth elements into the system and combining this with appropriate sintering atmosphere control, the binder phase forms a two-phase structure with coexisting crystalline and amorphous phases during sintering and cooling, thus improving the material's strength and toughness while maintaining its hardness.

[0011] Through the synergistic effect of the above-mentioned hard phase structure optimization and binder phase microstructure regulation, this invention can significantly reduce stress concentration at the interface between the ceramic phase and the metal binder phase, improve the interfacial bonding strength, enhance the strength and hardness of the metal-ceramic binder phase, and further improve the impact toughness, fracture toughness and comprehensive mechanical properties of TiC and Ti(C,N) based metal ceramics.

[0012] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0013] This invention provides a dual-phase reinforced rare-earth Ti-based cermet, comprising the following components by mass percentage:

[0014] The composition is a multi-component Ti-based solid solution ceramic phase of 60-70%, a carbide phase of 15-25%, a metallic binder phase of 12-23%, and a rare earth oxide phase of 0.1-0.8%.

[0015] The metallic binder phase is a two-phase structure in which amorphous and crystalline phases coexist.

[0016] Preferably, the multi-component Ti-based solid solution ceramic phase is (Ti X Mo Y (C) A N B ) or (Ti X Mo Y C;

[0017] Where X is 0.93~0.98, Y is 0.02~0.07, and X+Y=1;

[0018] A is 0.3~0.7, B is 0.3~0.7, and A+B=1.

[0019] Preferably, the carbide phase is one or more of WC, TaC, NbC, ZrC, Cr3C2 and VC;

[0020] The metallic binder phase is one or more of Co, Ni, and Fe.

[0021] Preferably, the rare earth oxide phase is one or more of Y2O3, Gd2O3, CeO2, La2O3, Sc2O3, Nd2O3 and Lu2O3.

[0022] This invention also provides a method for preparing the aforementioned dual-phase reinforced rare-earth Ti-based cermet, comprising the following steps:

[0023] 1) Put (Ti) X Mo Y (C) A N B ) or (Ti X Mo Y C powder, carbide phase powder, metal binder phase powder and rare earth nitrate are mixed;

[0024] 2) Add a molding agent to the mixed powder, then wet grind it, and then spray granulate and press it to form a green body.

[0025] 3) The green body is subjected to partial pressure sintering in a protective atmosphere to obtain a dual-phase reinforced rare earth Ti-based metal ceramic.

[0026] Preferably, the rare earth nitrate in step 1) is one or more of Y(NO3)3, Gd(NO3)3, Ce(NO3)3, La(NO3)3, Sc(NO3)3, Nd(NO3)3 and Lu(NO3)3.

[0027] Preferably, the molding agent in step 2) is paraffin wax, and the amount of molding agent added is 3~4.5% of the powder mass; in the wet grinding process, the grinding balls are cemented carbide grinding balls, the grinding medium is anhydrous ethanol, the ball-to-material ratio is 8~10:1, the grinding speed is 150~300 r / min, and the grinding time is 48~72 h.

[0028] Preferably, in step 2), the atomization pressure of the spray granulation is 0.5~1.5MPa, the inlet air temperature is 180~240℃, the outlet air temperature is 70~100℃, and after the spray granulation is completed, the average particle size of the obtained particles is 60~120μm.

[0029] The pressing pressure is 100~220MPa, and the time is 3~15s.

[0030] Preferably, the partial pressure sintering temperature in step 3) is 1410~1510℃, the pressure is 10~80mbar, and the time is 1~2h;

[0031] The protective atmosphere is one or more of the following: a mixture of helium and nitrogen, a mixture of helium and argon, and pure helium.

[0032] The present invention also provides the application of the aforementioned dual-phase reinforced rare earth Ti-based cermet in wear-resistant liners and wear-resistant irregular parts for mining machinery, TC bearings for oil drilling, guide rollers, and metal cutting tools.

[0033] The beneficial effects of this invention include the following:

[0034] 1) This invention introduces rare earth nitrates into the system, which decompose during sintering to form rare earth oxides, thereby making rare earth elements uniformly distributed at the interface between the ceramic phase and the metal binder phase. This improves the interface structure and enhances the amorphous formation ability of the binder phase, which is conducive to the formation of a dual-phase structure in the binder phase where amorphous and crystalline phases coexist, thereby improving the strength and wear resistance of the metal ceramic.

[0035] 2) In the partial pressure sintering process, the present invention uses a mixture of helium and nitrogen, a mixture of helium and argon, or pure helium as a protective atmosphere. Since helium has a high thermal conductivity, it can improve the heat transfer efficiency during the cooling process, thereby increasing the cooling rate. This is beneficial to retaining the amorphous structure in the binder phase and further improving the comprehensive mechanical properties of the material.

[0036] 3) This invention uses (Ti) X Mo Y (C) A N B ) or (Ti X Mo Y Using C as a hard phase raw material, Mo is introduced into the metal ceramic system in the form of a solid solution. Combined with the regulation of rare earth elements, the amount of Mo dissolved in the metal binder phase can be effectively controlled while giving full play to the strengthening effect of Mo. This avoids the formation of too much or pure amorphous structure in the binder phase, and finally obtains a binder phase structure in which amorphous phase and crystalline phase coexist, thereby improving the fracture toughness and comprehensive mechanical properties of the material. Attached Figure Description

[0037] Figure 1 The image shows the microstructure of the dual-phase reinforced rare-earth Ti-based cermet prepared in Example 1.

[0038] Figure 2The image shows the elemental composition distribution of the dual-phase reinforced rare earth Ti-based cermet prepared in Example 1. Detailed Implementation

[0039] This invention provides a dual-phase reinforced rare-earth Ti-based cermet, comprising the following components by mass percentage:

[0040] The composition is a multi-component Ti-based solid solution ceramic phase of 60-70%, a carbide phase of 15-25%, a metallic binder phase of 12-23%, and a rare earth oxide phase of 0.1-0.8%.

[0041] The metallic binder phase is a two-phase structure in which amorphous and crystalline phases coexist.

[0042] The dual-phase reinforced rare earth Ti-based metal ceramic of the present invention comprises a multi-component Ti-based solid solution ceramic phase with a mass percentage of 60-70%, preferably 62-68%, more preferably 64-66%, and even more preferably 65%.

[0043] In this invention, the multi-component Ti-based solid solution ceramic phase is preferably (Ti X Mo Y (C) A N B ) or (Ti X Mo Y C;

[0044] Wherein, X is preferably 0.93~0.98, more preferably 0.94~0.96, and even more preferably 0.95; Y is preferably 0.02~0.07, more preferably 0.04~0.06, and even more preferably 0.05, and preferably X+Y=1;

[0045] A is preferably 0.3~0.7, more preferably 0.4~0.6, and even more preferably 0.5; B is preferably 0.3~0.7, more preferably 0.4~0.6, and even more preferably 0.5, and preferably A+B=1.

[0046] The dual-phase reinforced rare-earth Ti-based cermet of the present invention contains 15-25% by mass of carbide phase, preferably 16-24%, more preferably 18-22%, and even more preferably 20%.

[0047] In this invention, the carbide phase is preferably one or more of WC, TaC, NbC, ZrC, Cr3C2 and VC.

[0048] The dual-phase reinforced rare earth Ti-based cermet of the present invention contains 12-23% by mass of a metal binder phase, preferably 14-20%, more preferably 15-18%, and more preferably 16%.

[0049] In this invention, the metal binder phase is preferably one or more of Co, Ni and Fe.

[0050] The dual-phase reinforced rare earth Ti-based cermet of the present invention contains 0.1-0.8% by mass of rare earth oxide phase, preferably 0.2-0.6%, more preferably 0.2-0.5%, and more preferably 0.2%.

[0051] In this invention, the rare earth oxide phase is preferably one or more of Y2O3, Gd2O3, CeO2, La2O3, Sc2O3, Nd2O3 and Lu2O3.

[0052] The present invention also provides a method for preparing the aforementioned dual-phase reinforced rare-earth Ti-based cermet, preferably comprising the following steps:

[0053] 1) Put (Ti) X Mo Y (C) A N B ) or (Ti X Mo Y C powder, carbide phase powder, metal binder phase powder and rare earth nitrate are mixed;

[0054] 2) Add a molding agent to the mixed powder, then wet grind it, and then spray granulate and press it to form a green body.

[0055] 3) The green body is subjected to partial pressure sintering in a protective atmosphere to obtain a dual-phase reinforced rare earth Ti-based metal ceramic.

[0056] In this invention, the rare earth nitrate in step 1) is preferably one or more of Y(NO3)3, Gd(NO3)3, Ce(NO3)3, La(NO3)3, Sc(NO3)3, Nd(NO3)3 and Lu(NO3)3.

[0057] In this invention, the rare earth nitrates in step 1) can decompose during the sintering process to form rare earth oxides.

[0058] In this invention, the molding agent in step 2) is preferably paraffin wax, and the amount of molding agent added is preferably 3-4.5% of the powder mass, more preferably 3.5-4.5%, and even more preferably 4.0%; in the wet grinding process, the grinding balls are preferably cemented carbide grinding balls; the grinding medium is preferably anhydrous ethanol; the ball-to-material ratio is preferably 8-10:1, more preferably 9:1; the grinding speed is preferably 150-300 r / min, more preferably 200-300 r / min, and even more preferably 250 r / min; the grinding time is preferably 48-72 h, more preferably 55-65 h, and even more preferably 60 h.

[0059] In this invention, the atomization pressure of the spray granulation in step 2) is preferably 0.5~1.5MPa, more preferably 0.8~1.2MPa, and even more preferably 1MPa; the inlet air temperature is preferably 180~240℃, more preferably 200~220℃, and even more preferably 210℃; the outlet air temperature is preferably 70~100℃, more preferably 80~90℃, and even more preferably 85℃; after spray granulation, the average particle size of the obtained particles is preferably 60~120μm, more preferably 80~100μm, and even more preferably 90μm.

[0060] The pressing pressure is preferably 100~220MPa, more preferably 150~200MPa, and even more preferably 180MPa; the time is preferably 3~15s, more preferably 5~10s, and even more preferably 6~8s.

[0061] In this invention, the temperature of the partial pressure sintering in step 3) is preferably 1410~1510℃, more preferably 1430~1480℃, and even more preferably 1440~1470℃; the pressure is preferably 10~80mbar, more preferably 20~60mbar, and even more preferably 30~50mbar; the time is preferably 1~2h, more preferably 1.0~1.6h, and even more preferably 1.2h.

[0062] The protective atmosphere is preferably one or more of the following: a mixture of helium and nitrogen, a mixture of helium and argon, and pure helium.

[0063] The present invention also provides the application of the aforementioned dual-phase reinforced rare earth Ti-based cermet in wear-resistant liners and wear-resistant irregular parts for mining machinery, TC bearings for oil drilling, guide rollers, and metal cutting tools.

[0064] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0065] Example 1

[0066] Weigh out 500g (Ti0.94 Mo 0.06 (C) 0.5 N 0.5 120g of WC powder and 38g of TaC powder were used as the multi-component Ti-based solid solution ceramic phase powder, 70g of Ni powder and 70g of Co powder were used as the metal binder phase powder, and 2.4g of Y(NO3)3·5H2O was added as rare earth nitrate, and a small amount of C powder was added for mixing.

[0067] Subsequently, paraffin wax was added to the above mixed powder as a forming agent (the amount of paraffin wax added was 4% of the powder mass), and wet grinding was carried out under the condition of cemented carbide grinding balls with a particle size of 12 mm. The wet grinding medium was anhydrous ethanol, the amount of anhydrous ethanol was 420 mL, the ball-to-powder ratio was 10:1, the ball milling speed was 150 r / min, and the ball milling time was 72 h.

[0068] After wet grinding, a uniform slurry is obtained. The slurry is then subjected to spray granulation treatment. The atomization pressure of spray granulation is 1 MPa, the inlet air temperature is 220℃, and the outlet air temperature is 95℃. After spray granulation, the average particle size of the obtained particles is 80 μm. The obtained granulated powder is then pressed into shape. The pressing pressure is 180 MPa, and the holding time is 4 s to obtain a green body.

[0069] The green body was subjected to partial pressure sintering under a mixed gas of helium and nitrogen (volume ratio of helium to nitrogen of 1:3). The partial pressure sintering temperature was 1450℃, the pressure was 50mbar, and the time was 1h. Then it was rapidly cooled to 80℃ to obtain a dual-phase reinforced rare earth Ti-based metal ceramic.

[0070] Phase composition analysis showed that the mass percentages of the multi-component Ti-based solid solution ceramic phase, carbide phase, metal binder phase, and rare earth oxide phase in the obtained dual-phase reinforced rare earth Ti-based cermet were 62.5%, 19.8%, 17.5%, and 0.2%, respectively.

[0071] The microstructure of the dual-phase reinforced rare-earth Ti-based cermet prepared in this embodiment is shown in the figure below. Figure 1 As shown. By Figure 1 It can be seen that the metal binder region exhibits a dual-phase structure characterized by the coexistence of amorphous and crystalline phases.

[0072] The elemental composition distribution diagram of the dual-phase reinforced rare-earth Ti-based cermet prepared in this embodiment is shown in the figure below. Figure 2 As shown. By Figure 2 It can be seen that the elements are evenly distributed in the material.

[0073] Example 2

[0074] Weigh out 500g (Ti 0.93 Mo0.07 C powder was used as the multi-component Ti-based solid solution ceramic phase powder, 100g WC powder and 38g NbC powder were used as the carbide phase powder, 60g Ni powder and 70g Fe powder were used as the metal binder phase powder, and 2.4g Gd(NO3)3·4H2O was added as rare earth nitrate, and a small amount of C powder was added for mixing.

[0075] Subsequently, paraffin wax was added to the above mixed powder as a forming agent (the amount of paraffin wax added was 4.5% of the powder mass), and wet grinding was carried out under the condition of cemented carbide grinding balls with a particle size of 12 mm. The wet grinding medium was anhydrous ethanol, the amount of anhydrous ethanol was 430 mL, the ball-to-powder ratio was 8:1, the ball milling speed was 200 r / min, and the ball milling time was 60 h.

[0076] After wet milling, a uniform slurry is obtained. The slurry is then subjected to spray granulation treatment. The atomization pressure of spray granulation is 0.5 MPa, the inlet air temperature is 180℃, and the outlet air temperature is 70℃. After spray granulation, the average particle size of the obtained particles is 60 μm. The obtained granulated powder is then pressed into shape. The pressing pressure is 100 MPa, and the holding time is 15 s to obtain a green body.

[0077] The blank was subjected to partial pressure sintering under a mixed gas of helium and argon (volume ratio of helium to argon of 1:3). The partial pressure sintering temperature was 1410℃, the pressure was 10mbar, and the time was 2h. Then it was rapidly cooled to 80℃ to obtain a dual-phase reinforced rare earth Ti-based metal ceramic.

[0078] Phase composition analysis showed that the mass percentages of the multi-component Ti-based solid solution ceramic phase, carbide phase, metal binder phase, and rare earth oxide phase in the obtained dual-phase reinforced rare earth Ti-based cermet were 65%, 17.9%, 16.9%, and 0.2%, respectively.

[0079] Example 3

[0080] Weigh out 450g (Ti 0.98 Mo 0.02 (C) 0.3 N 0.7 The powder was used as a multi-component Ti-based solid solution ceramic phase powder, 80g NbC powder and 30g ZrC powder were used as carbide phase powder, 50g Ni powder and 50g Co powder were used as metal binder phase powder, and 1.2g Ce(NO3)3·6H2O was added as rare earth nitrate, and a small amount of C powder was added for mixing.

[0081] Subsequently, paraffin wax was added to the above mixed powder as a forming agent (the amount of paraffin wax added was 4% of the powder mass), and wet grinding was carried out under the condition of cemented carbide grinding balls with a particle size of 12 mm. The wet grinding medium was anhydrous ethanol, the amount of anhydrous ethanol was 440 mL, the ball-to-powder ratio was 9:1, the ball milling speed was 300 r / min, and the ball milling time was 48 h.

[0082] After wet grinding, a uniform slurry is obtained. The slurry is then subjected to spray granulation treatment. The atomization pressure of spray granulation is 1.5 MPa, the inlet air temperature is 240℃, and the outlet air temperature is 100℃. After spray granulation, the average particle size of the obtained particles is 110 μm. The obtained granulated powder is then pressed into shape. The pressing pressure is 220 MPa, and the holding time is 3 s to obtain a green body.

[0083] The green body was subjected to partial pressure sintering under pure helium conditions at a temperature of 1510℃, a pressure of 80mbar, and a time of 1.5h. It was then rapidly cooled to 80℃ to obtain a dual-phase reinforced rare earth Ti-based metal ceramic.

[0084] Phase composition analysis showed that the mass percentages of the multi-component Ti-based solid solution ceramic phase, carbide phase, metal binder phase, and rare earth oxide phase in the obtained dual-phase reinforced rare earth Ti-based metal ceramic were 68.1%, 16.6%, 15.1%, and 0.2%, respectively.

[0085] Comparative Example 1

[0086] Weigh out 455g of Ti (C) 0.5 N 0.5 45g Mo2C, 120g WC, and 38g TaC were used as the multi-component Ti-based solid solution ceramic phase powder, 70g Ni powder and 70g Co powder were used as the metal binder phase powder, and 1.6g Y(NO3)3·5H2O was added as rare earth nitrate, and a small amount of C powder was added for mixing.

[0087] Subsequently, paraffin wax was added to the above mixed powder as a forming agent (the amount of paraffin wax added was 3% of the powder mass), and wet grinding was carried out under the condition of cemented carbide grinding balls with a particle size of 12 mm. The wet grinding medium was anhydrous ethanol, the amount of anhydrous ethanol was 420 mL, the ball-to-powder ratio was 10:1, the ball milling speed was 200 r / min, and the ball milling time was 72 h.

[0088] After wet grinding, a uniform slurry is obtained. The slurry is then subjected to spray granulation treatment. The atomization pressure of spray granulation is 1 MPa, the inlet air temperature is 220℃, and the outlet air temperature is 95℃. After spray granulation, the average particle size of the obtained particles is 85 μm. The obtained granulated powder is then pressed into shape. The pressing pressure is 180 MPa, and the holding time is 4 s to obtain a green body.

[0089] The green body was subjected to partial pressure sintering in a mixed gas of helium and nitrogen (volume ratio of helium to nitrogen of 1:3). The partial pressure sintering temperature was 1460℃, the pressure was 50mbar, and the time was 1h. Then it was rapidly cooled to 80℃ to obtain Ti-based cermet.

[0090] Comparative Example 2

[0091] Weigh 455g of TiC powder as the multi-component Ti-based solid solution ceramic phase powder, 45g of Mo2C, 120g of WC, and 38g of TaC as the carbide phase powder, 70g of Ni powder and 70g of Co powder as the metal binder phase powder, and add 1.6g of Y(NO3)3·5H2O as rare earth nitrate, and add a small amount of C powder for mixing.

[0092] Subsequently, paraffin wax was added to the above mixed powder as a forming agent (the amount of paraffin wax added was 3% of the powder mass), and wet grinding was carried out under the condition of cemented carbide grinding balls with a particle size of 12 mm. The wet grinding medium was anhydrous ethanol, the amount of anhydrous ethanol was 420 mL, the ball-to-powder ratio was 10:1, the ball milling speed was 200 r / min, and the ball milling time was 72 h.

[0093] After wet grinding, a uniform slurry is obtained. The slurry is then subjected to spray granulation treatment. The atomization pressure of spray granulation is 1 MPa, the inlet air temperature is 220℃, and the outlet air temperature is 95℃. After spray granulation, the particle size of the obtained particles is 80 μm. The obtained granulated powder is then pressed into shape. The pressing pressure is 180 MPa, and the holding time is 4 s to obtain a green body.

[0094] The green body was subjected to partial pressure sintering in a mixed gas of helium and nitrogen (volume ratio of helium to nitrogen of 1:3). The partial pressure sintering temperature was 1460℃, the pressure was 50mbar, and the time was 1h. Then it was rapidly cooled to 80℃ to obtain Ti-based cermet.

[0095] The properties of the Ti-based cermets prepared in Examples 1-3 and Comparative Examples 1-2 were measured, and the results are shown in Table 1.

[0096] The test method for Vickers hardness of cermet alloys adopts the national standard GB 7997-87; the test method for fracture toughness adopts the national standard GB / T 12616-2016; and the test method for impact toughness adopts the national standard GB / T 1817-2017.

[0097] Table 1. Performance test results of Ti-based cermets prepared in Examples 1-3 and Comparative Examples 1-2

[0098] As shown in Table 1, the Vickers hardness, fracture toughness and impact toughness of the Ti-based metal ceramics prepared in Examples 1-3 are all better than those of the Ti-based metal ceramics prepared in Comparative Examples 1-2.

[0099] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A dual-phase reinforced rare-earth Ti-based cermet, characterized in that, Components comprising the following mass percentages: The composition is a multi-component Ti-based solid solution ceramic phase of 60-70%, a carbide phase of 15-25%, a metallic binder phase of 12-23%, and a rare earth oxide phase of 0.1-0.8%. The metallic binder phase is a two-phase structure in which amorphous and crystalline phases coexist.

2. The dual-phase reinforced rare-earth Ti-based cermet according to claim 1, characterized in that, The multi-component Ti-based solid solution ceramic phase is (Ti X Mo Y (C) A N B ) or (Ti X Mo Y C; Where X is 0.93~0.98, Y is 0.02~0.07, and X+Y=1; A is 0.3~0.7, B is 0.3~0.7, and A+B=1.

3. The dual-phase reinforced rare-earth Ti-based cermet according to claim 1 or 2, characterized in that, The carbide phase is one or more of WC, TaC, NbC, ZrC, Cr3C2 and VC; The metallic binder phase is one or more of Co, Ni, and Fe.

4. The dual-phase reinforced rare-earth Ti-based metal ceramic according to claim 3, characterized in that, The rare earth oxide phase is one or more of Y2O3, Gd2O3, CeO2, La2O3, Sc2O3, Nd2O3 and Lu2O3.

5. The method for preparing dual-phase reinforced rare-earth Ti-based cermets according to any one of claims 1 to 4, characterized in that, It includes the following steps: 1) Put (Ti) X Mo Y (C) A N B ) or (Ti X Mo Y C powder, carbide phase powder, metal binder phase powder and rare earth nitrate are mixed; 2) Add a molding agent to the mixed powder, then wet grind it, and then spray granulate and press it to form a green body. 3) The green body is subjected to partial pressure sintering in a protective atmosphere to obtain a dual-phase reinforced rare earth Ti-based metal ceramic.

6. The preparation method according to claim 5, characterized in that, Step 1) The rare earth nitrate is one or more of Y(NO3)3, Gd(NO3)3, Ce(NO3)3, La(NO3)3, Sc(NO3)3, Nd(NO3)3 and Lu(NO3)3.

7. The preparation method according to claim 5, characterized in that, Step 2) The forming agent is paraffin wax, and the amount of forming agent added is 3-4.5% of the powder mass; in the wet grinding process, the grinding balls are... The grinding media is anhydrous ethanol, the ball-to-material ratio is 8~10:1, the grinding speed is 150~300 r / min, and the grinding time is 48~72 h.

8. The preparation method according to claim 5, characterized in that, Step 2) The atomization pressure of the spray granulation is 0.5~1.5MPa, the inlet air temperature is 180~240℃, the outlet air temperature is 70~100℃, and after the spray granulation is completed, the average particle size of the obtained particles is 60~120μm. The pressing pressure is 100~220MPa, and the time is 3~15s.

9. The preparation method according to claim 5, characterized in that, Step 3) The partial pressure sintering temperature is 1410~1510℃, the pressure is 10~80mbar, and the time is 1~2h; The protective atmosphere is one or more of the following: a mixture of helium and nitrogen, a mixture of helium and argon, and pure helium.

10. The application of the dual-phase reinforced rare earth Ti-based cermet as described in any one of claims 1 to 4 in wear-resistant liners and wear-resistant profiled parts for mining machinery, TC bearings for oil drilling, guide rollers, or metal cutting tools.

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