Titanium-based hard alloy and tungsten carbide hard alloy complex and preparation method thereof

Abstract

The invention provides a complex of a titanium-based hard alloy and a tungsten carbide hard alloy. The complex is composed of the titanium-based hard alloy and the tungsten carbide hard alloy. The hard phase of the titanium-based hard alloy is selected from one or two of TiC and Ti (C, N), and the binding phase comprises one or more of Co, Ni and Fe; the hard phase of the tungsten carbide hard alloy is WC, and the binding phase comprises one or more of Co, Ni and Fe. The invention further provides a preparation method of the complex. According to the composite body of the titanium-based hard alloy and the tungsten carbide hard alloy, the advantages that the titanium-based hard alloy part is high in hardness and good in wear resistance, and the tungsten carbide hard alloy part is high in strength and high in impact resistance are utilized, so that a composite structure with high hardness and high strength is achieved; the complex can be used under various complex working conditions such as wear resistance and impact resistance.

Description

Technical Field

[0001] The invention relates to the technical field of cemented carbide, and in particular to a composite of titanium-based cemented carbide and tungsten carbide cemented carbide and a preparation method thereof. Background Art

[0002] Tungsten carbide is a high-performance material composed of tungsten carbide powder and metal binder. It plays an important role in the industry with its excellent physical and chemical properties. The high strength, high hardness, excellent wear resistance and thermal stability of tungsten carbide make it an important material in key areas such as cutting tools, resistant parts and mining tools.

[0003] Titanium-based cemented carbide is a cemented carbide with TiC or Ti(C, N) as the main component and Ni-Mo or Ni-Co-Mo as the binder phase. Since the melting point of TiC (up to 3250℃) is higher than that of WC (2630℃), and the density is only 1 / 2 to 1 / 3 of that of tungsten carbide, the lighter titanium-based cemented carbide has a relatively high hardness and high wear resistance compared to tungsten carbide, except that its bending strength is slightly weaker than that of tungsten carbide, and its high-temperature oxidation resistance is better. Titanium-based cemented carbide has a lower density and is cheaper without reducing physical properties, which can meet more lightweight design demand scenarios. W and Co are expensive and scarce resources. Therefore, titanium-based alloys have more cost advantages and application advantages in replacing tungsten carbide.

[0004] The titanium-based cemented carbide products and tungsten carbide cemented carbide products are compounded together to form a new type of high-performance and low-cost cemented carbide composite with complementary advantages and strong combination. This allows the two to give full play to the maximum advantages of their own materials, which not only reduces the cost of alloy materials, but also reduces the overall weight of the composite workpiece, meeting the lightweight design requirements of modern equipment, and has important significance and application value.

[0005] The Chinese patent with publication number CN113831148A discloses a titanium carbide-based ceramic and hard alloy welding round rod and its preparation method. The welding method is only suitable for the situation where the bonding surface is simple and the area is small, and the metallurgical bonding of the two materials cannot be achieved. The bonding strength is limited, resulting in the product being very easy to fail due to cracking at the bonding point. The Chinese patent with publication number CN116197503A discloses a welding part of hard alloy and steel and its preparation method, which uses the plasma activation effect, particle self-cleaning effect, Joule heat, and electric and magnetic fields generated by pulsed direct current during discharge plasma sintering to achieve fast high-quality connection of hard alloy and steel at a lower temperature. However, in fact, the thermal expansion coefficients of two different materials, hard alloy and steel, are quite different, and stress cracking and poor welding rate are easily caused after welding. More importantly, the hardness and wear resistance of the steel part itself are poor, far inferior to that of the hard alloy material, so it is impossible to completely replace it, which ultimately affects the overall performance and service life of the workpiece.

[0006] Therefore, how to combine titanium-based cemented carbide and tungsten carbide, two heterogeneous materials with large differences in thermal expansion coefficients, has always been a difficult problem that is difficult to solve in the cemented carbide industry. Summary of the invention

[0007] The technical problem solved by the present invention is to provide a composite of titanium-based cemented carbide and tungsten carbide cemented carbide. The composite provided by the present application realizes good metallurgical bonding of titanium-based cemented carbide and tungsten carbide cemented carbide, and has both high strength and high hardness.

[0008] In view of this, the present application provides a composite of titanium-based cemented carbide and tungsten carbide cemented carbide, which is composed of titanium-based cemented carbide and tungsten carbide cemented carbide;

[0009] Based on the mass of titanium-based cemented carbide, the hard phase of the titanium-based cemented carbide is selected from one or two of TiC and Ti(C, N), with a content of 70-96wt%, and the binding phase includes one or more of Co, Ni and Fe, with a content of 4-30wt%;

[0010] Based on the mass of tungsten carbide, the hard phase of tungsten carbide is WC, the content is 70-96wt%, and the binding phase includes one or more of Co, Ni and Fe, the content is 4-30wt%;

[0011] The carbon content of the alloy with high binder phase content in the composite increases by 0-0.05wt% on the basis of carbon balance, and the carbon content of the alloy with low binder phase content in the composite decreases by 0-0.05wt% on the basis of carbon balance.

[0012] Preferably, the absolute value of the difference between the binder phase content of the titanium-based cemented carbide and the binder phase content of the tungsten carbide cemented carbide is 0-10wt%.

[0013] Preferably, the absolute value of the difference between the binder phase content of the titanium-based cemented carbide and the binder phase content of the tungsten carbide cemented carbide is 1-5wt%.

[0014] Preferably, the titanium-based cemented carbide and / or the tungsten carbide cemented carbide further comprises TaC, NbC, Cr 3 C 2 , VC and Mo or more.

[0015] Preferably, based on the mass of tungsten carbide, the content of hard phase is 85-92wt%, and the content of bonding phase is 6-18wt%; based on the mass of titanium-based cemented carbide, the content of hard phase is 85-92wt%, and the content of bonding phase is 6-18wt%.

[0016] The present application also provides a method for preparing the complex, comprising the following steps:

[0017] The titanium-based cemented carbide mixture and the tungsten carbide cemented carbide mixture are placed in different areas of the preparation device, and then pressed into shape to obtain a green body;

[0018] The green body is pressure-sintered to obtain a composite body.

[0019] Preferably, the titanium-based cemented carbide mixture further comprises a molding agent, and the molding agent is 1 to 5 wt % of the titanium-based cemented carbide mixture;

[0020] And / or, the tungsten carbide cemented carbide mixture further includes a molding agent, and the molding agent is 1 to 5 wt % of the tungsten carbide cemented carbide mixture;

[0021] The molding agent includes one or more of paraffin, polyethylene glycol and rubber.

[0022] Preferably, the press molding specifically includes pre-pressing and cold isostatic pressing performed sequentially.

[0023] Preferably, the pre-pressing pressure is 10 to 120 MPa, and the cold isostatic pressing pressure is 50 to 300 MPa.

[0024] Preferably, the pressure of the pressure sintering is 1-12 MPa, the temperature is 1200-1600° C., and the time is 0.3-3 h.

[0025] The present application provides a composite of titanium-based cemented carbide and tungsten carbide, which is composed of titanium-based cemented carbide and tungsten carbide; based on the mass of the titanium-based cemented carbide, the hard phase of the titanium-based cemented carbide is one or two of TiC and Ti(C, N), with a content of 70-96wt%, and the bonding phase includes one or more of Co, Ni and Fe, with a content of 4-30wt%; based on the mass of the tungsten carbide cemented carbide, the hard phase of the tungsten carbide is WC, with a content of 70-96wt%, and the bonding phase includes one or more of Co, Ni and Fe, with a content of 4-30wt%; the carbon content corresponding to the alloy with a high bonding phase content in the composite is increased by 0-0.05wt% on the basis of carbon balance, and the carbon content corresponding to the alloy with a low bonding phase content in the composite is reduced by 0-0.05wt% on the basis of carbon balance. The composite provided in the present application regulates the actual carbon content of titanium-based cemented carbide and tungsten carbide according to the content relationship of the bonding phase, which can achieve improved impact resistance and wear resistance, while limiting the bonding phase content in titanium-based cemented carbide and tungsten carbide to ensure the metallurgical bonding of titanium-based cemented carbide and tungsten carbide. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A metallographic photograph of the titanium-based cemented carbide provided in Example 1 of the present invention;

[0027] Figure 2 A metallographic photograph of tungsten carbide provided in Example 1 of the present invention;

[0028] Figure 3 A metallographic photograph of the interface of the composite of titanium-based cemented carbide and tungsten carbide cemented carbide prepared in Example 1 of the present invention;

[0029] Figure 4 This is a photo of a composite of titanium-based cemented carbide and tungsten carbide cemented carbide prepared in an example of the present invention. DETAILED DESCRIPTION

[0030] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0031] In view of the problem of metallurgical bonding between titanium-based cemented carbide and tungsten carbide in the prior art, the present application provides a composite of titanium-based cemented carbide and tungsten carbide, which is composed of titanium-based cemented carbide and tungsten carbide, and at the same time regulates the hard phase, bonding phase and carbon content of titanium-based cemented carbide and tungsten carbide, so that the obtained composite has good metallurgical bonding and has both high hardness and high strength, so that the composite can be used in a variety of composite working conditions such as wear resistance and impact resistance. Specifically, the embodiment of the present invention discloses a composite of titanium-based cemented carbide and tungsten carbide, which is composed of titanium-based cemented carbide and tungsten carbide;

[0032] Based on the mass of titanium-based cemented carbide, the hard phase of the titanium-based cemented carbide is one or two of TiC and Ti(C, N), with a content of 70-96wt%, and the binding phase includes one or more of Co, Ni and Fe, with a content of 4-30wt%;

[0033] Based on the mass of tungsten carbide, the hard phase of tungsten carbide is WC, the content is 70-96wt%, and the binding phase includes one or more of Co, Ni and Fe, the content is 4-30wt%;

[0034] The carbon content of the alloy with high binder phase content in the composite increases by 0-0.05wt% on the basis of carbon balance, and the carbon content of the alloy with low binder phase content in the composite decreases by 0-0.05wt% on the basis of carbon balance.

[0035] The composite of titanium-based cemented carbide and tungsten carbide provided in the present application is composed of titanium-based cemented carbide and tungsten carbide.

[0036] For titanium-based cemented carbide, the hard phase of the titanium-based cemented carbide is selected from one or two of TiC and Ti(C, N), and the content is 70-96wt%. Specifically, the content of the hard phase is 85-92wt%, and more specifically, the content of the hard phase is 88-90wt%. The binding phase includes one or more of Co, Ni and Fe, and the content is 4-30wt%; specifically, the binding phase is selected from one or more of Co, Ni and Fe, and more specifically, the binding phase is selected from Co and Ni. Specifically, the content of the binding phase is 6-18wt%; more specifically, the content of the binding phase is 7-14wt%; more specifically, the content of the binding phase is 9-13wt%. The titanium-based cemented carbide also includes TaC, NbC, Cr 3 C 2 , VC and Mo, and the content of the above components is 1 to 5wt%.

[0037] For tungsten carbide cemented carbide, the hard phase of tungsten carbide is selected from WC, and the content is 70-96wt%. Specifically, the content of the hard phase is 85-92wt%, and more specifically, the content of the hard phase is 88-90wt%. The bonding phase includes one or more of Co, Ni and Fe, and the content is 4-30wt%; specifically, the bonding phase is selected from one or more of Co, Ni and Fe, and more specifically, the bonding phase is selected from Co and Ni. Specifically, the content of the bonding phase is 6-18wt%; more specifically, the content of the bonding phase is 7-14wt%; more specifically, the content of the bonding phase is 9-13wt%. The tungsten carbide also includes TaC, NbC, Cr 3 C 2 , VC and Mo, and the content of the above components is 1 to 5wt%.

[0038] In the composite, the carbon content of the alloy with high binder phase content in the composite increases by 0-0.05wt% on the basis of carbon balance, and the carbon content of the alloy with low binder phase content in the composite decreases by 0-0.05wt% on the basis of carbon balance; specifically, the carbon content of the alloy with high binder phase content in the composite increases by 0.01wt%, 0.02wt%, 0.03wt%, 0.04wt% or 0.05wt% on the basis of carbon balance, and the carbon content of the alloy with low binder phase content in the composite decreases by 0.01wt%, 0.02wt%, 0.03wt%, 0.04wt% or 0.05wt% on the basis of carbon balance. In the above regulation, the carbon content of the cemented carbide with relatively high binder phase content increases to 0.05wt% on the basis of carbon balance to enhance impact resistance, and the carbon content of the cemented carbide with relatively low binder phase content decreases to 0.05wt% on the basis of carbon balance to enhance wear resistance.

[0039] Furthermore, the absolute value of the difference between the bonding phase content of the titanium-based cemented carbide and the bonding phase content of the tungsten carbide cemented carbide is 0-10wt%; specifically, the absolute value of the difference between the bonding phase content of the titanium-based cemented carbide and the bonding phase content of the tungsten carbide cemented carbide is 0-5wt%; this difference can ensure good liquid phase migration.

[0040] The present application also provides a method for preparing a titanium-based cemented carbide and tungsten carbide cemented carbide composite, comprising the following steps:

[0041] The titanium-based cemented carbide mixture and the tungsten carbide cemented carbide mixture are placed in different areas of the preparation device, and then pressed into shape to obtain a green body; a partition is arranged between the different areas;

[0042] The green body is pressure-sintered to obtain a composite body.

[0043] In the preparation process of titanium-based cemented carbide and tungsten carbide cemented carbide composites, titanium-based cemented carbide mixtures and tungsten carbide cemented carbide mixtures are first prepared respectively. The preparation of the titanium-based cemented carbide mixture is carried out according to a method well known to those skilled in the art, that is, hard phase raw materials, bonding phase raw materials and other additive raw materials are mixed according to the raw material ratio. Furthermore, a molding agent can be added to the obtained mixture, and the molding agent is selected from one or more of paraffin, polyethylene glycol and rubber. Specifically, the molding agent is selected from one of paraffin, polyethylene glycol and rubber; the molding agent is 1-5wt% of the mixture, and specifically, the molding agent is 2-4wt% of the mixture. Similarly, the preparation of the tungsten carbide cemented carbide mixture is carried out according to a method well known to those skilled in the art, that is, the hard phase raw material, the bonding phase raw material and other additive raw materials are mixed according to the raw material ratio, and further, a molding agent can be added to the obtained mixture, and the molding agent is selected from one or more of paraffin, polyethylene glycol and rubber, and specifically, the molding agent is selected from one of paraffin, polyethylene glycol and rubber; the molding agent is 1-5wt% of the mixture, and specifically, the molding agent is 2-4wt% of the mixture. In the present application, the molding agent is the same molding agent in titanium-based cemented carbide and tungsten carbide cemented carbide, and the content of the molding agent is close to or the same.

[0044] The present application then places the titanium-based cemented carbide mixture and the tungsten carbide cemented carbide mixture in different areas of the preparation device respectively to achieve the zoned placement of the titanium-based cemented carbide and the tungsten carbide cemented carbide, preferably in a molding die, and places separation rings in different areas of the mold cavity of the mold to separate the two mixtures; after the two mixtures are placed, the separation rings are removed for subsequent pressing and molding to achieve a dense metallurgical bond; the placement position of the separation rings can be selected according to demand, and the present application does not impose any special restrictions on this.

[0045] According to the present invention, the two mixed materials are then pressed and formed to obtain a green body; the pressing and forming includes pre-pressing and then cold isostatic pressing in sequence; the pre-pressing pressure is 10 to 120 MPa, specifically, the pre-pressing pressure is 30 to 100 MPa, more specifically, the pre-pressing pressure is 40 to 70 MPa, more specifically, the pre-pressing pressure is 50 to 60 MPa; the cold isostatic pressing pressure is 50 to 300 MPa, specifically, the cold isostatic pressing pressure is 60 to 180 MPa, more specifically, the cold isostatic pressing pressure is 70 to 150 MPa, more specifically, the cold isostatic pressing pressure is 80 to 120 MPa, more specifically, the cold isostatic pressing pressure is 90 to 100 MPa.

[0046] The present application finally performs pressure sintering on the green body to obtain a composite body; the pressure of the pressure sintering is 1-12MPa, the temperature is 1200-1600°C, and the time is 0.3-3h; specifically, the pressure of the pressure sintering is 3-10MPa, the temperature is 1300-1500°C, and the time is 30-60min, more specifically, the pressure of the pressure sintering is 4-8MPa, the temperature is 1400-1480°C, and the time is 40-50min.

[0047] The present application provides a titanium-based cemented carbide and tungsten carbide cemented carbide composite and a preparation method thereof. In the composite, the titanium-based cemented carbide part has high hardness and good wear resistance, the tungsten carbide cemented carbide part has high strength and strong impact resistance, and the two different types of cemented carbides are metallurgically bonded with high bonding strength. The two alloys are integrated, and their bending strength can reach more than 2000MPa, which is much higher than the strength of ordinary welding, thereby achieving a composite structure with both high hardness and high strength. The structure can be used under various complex working conditions such as wear resistance and impact resistance; in addition, the density of the titanium-based cemented carbide is as low as 6 to 7g / cm 3 The density of tungsten carbide is basically 14g / cm 3 The cost of the same product can be reduced by more than 50%.

[0048] In order to further understand the present invention, the composite of titanium-based cemented carbide and tungsten carbide cemented carbide and the preparation method thereof provided by the present invention are described in detail below in conjunction with the embodiments. The protection scope of the present invention is not limited by the following embodiments.

[0049] Example 1

[0050] The composite of titanium-based cemented carbide and tungsten carbide is composed of titanium-based cemented carbide and tungsten carbide; wherein the hard phase of the titanium-based cemented carbide is TiC, the hard phase content is 85wt%, the binding phase is Co and Ni, the content is 14wt%, and the balance is 1wt%, including TaC, NbC, Cr 3 C 2 , VC and Mo; the hard phase of tungsten carbide is WC, the hard phase content is 85wt%, the bonding phase is Co and Ni, the bonding phase content is 14wt%, and the balance is 1wt%, including TaC, NbC, Cr 3 C 2 , VC and Mo;

[0051] According to the above ratio, TiC, Co, Ni, TaC, NbC, Cr 3 C 2 , VC and Mo are mixed, and then 1wt% of molding agent paraffin is added to the mixture to obtain a titanium-based hard alloy mixture;

[0052] According to the above ratio, WC, Co, Ni, TaC, NbC, Cr 3 C 2 , VC and Mo are mixed, and then 1wt% of molding agent paraffin is added to the mixture to obtain a tungsten carbide cemented carbide mixture;

[0053] The titanium-based cemented carbide mixture and the tungsten carbide cemented carbide mixture are respectively loaded into different parts of the die, and then pre-pressed and cold isostatically pressed. The pre-pressing pressure is 30MPa and the cold isostatic pressing pressure is 80MPa.

[0054] Finally, the obtained green body is pressurized and sintered at a sintering pressure of 5 MPa, a sintering temperature of 1400° C., and a sintering time of 30 minutes to obtain a composite of titanium-based cemented carbide and tungsten carbide cemented carbide having a bending strength greater than or equal to 2100 MPa.

[0055] Figure 1 A metallographic photograph of the titanium-based cemented carbide provided in Example 1 of the present invention; Figure 2 A metallographic photograph of tungsten carbide provided in Example 1 of the present invention; Figure 3 This is a metallographic photograph of the interface of the composite of titanium-based cemented carbide and tungsten carbide prepared in Example 1 of the present invention; as can be seen from Example 3, the left side is titanium carbide grains, and the right side is tungsten carbide grains, and the two form a good combination.

[0056] Figure 4 This is a photo of a composite of titanium-based cemented carbide and tungsten carbide prepared in an embodiment of the present invention. The outer layer is tungsten carbide, the inner layer is titanium carbide, and there is a metallurgical bonding transition layer between the two layers.

[0057] Example 2

[0058] The composite of titanium-based cemented carbide and tungsten carbide is composed of titanium-based cemented carbide and tungsten carbide; wherein the hard phase of the titanium-based cemented carbide is TiC, the hard phase content is 86wt%, the binding phase is Co and Ni, the content is 13wt%, and the balance is 1wt%, including TaC, NbC, Cr 3 C 2 , VC and Mo; the hard phase of tungsten carbide is WC, the hard phase content is 86wt%, the bonding phase is Co and Ni, the bonding phase content is 13wt%, and the balance is 1wt%, including TaC, NbC, Cr 3 C 2 , VC and Mo;

[0059] According to the above ratio, TiC, Co, Ni, TaC, NbC, Cr 3 C 2, VC and Mo are mixed, and 2wt% of molding agent rubber is added to the mixture to obtain a titanium-based hard alloy mixture;

[0060] According to the above ratio, WC, Co, Ni, TaC, NbC, Cr 3 C 2 , VC and Mo are mixed, and then 2wt% of molding agent rubber is added to the mixture to obtain a tungsten carbide cemented carbide mixture;

[0061] The titanium-based cemented carbide mixture and the tungsten carbide cemented carbide mixture are respectively loaded into different parts of the die, and then pre-pressed and cold isostatically pressed. The pre-pressing pressure is 40MPa and the cold isostatic pressing pressure is 100MPa.

[0062] Finally, the obtained green body is pressurized and sintered at a sintering pressure of 6 MPa, a sintering temperature of 1420° C., and a sintering time of 40 minutes to obtain a composite of titanium-based cemented carbide and tungsten carbide cemented carbide having a bending strength greater than or equal to 2200 MPa.

[0063] Example 3

[0064] The composite of titanium-based cemented carbide and tungsten carbide is composed of titanium-based cemented carbide and tungsten carbide; wherein the hard phase of the titanium-based cemented carbide is Ti (C, N), the hard phase content is 88wt%, the binding phase is Co and Ni, the content is 11wt%, and the balance is 1wt%, including TaC, NbC, Cr 3 C 2 , VC and Mo; the hard phase of tungsten carbide is WC, the hard phase content is 87wt%, the bonding phase is Co and Ni, the bonding phase content is 12wt%, and the balance is 1wt%, including TaC, NbC, Cr 3 C 2 , VC and Mo; wherein the carbon content of tungsten carbide in the carbon balance of tungsten carbide is 6.13wt%, and the carbon content in the tungsten carbide is adjusted to make the carbon content of tungsten carbide 6.18wt%; the carbon content of Ti(C, N) in the titanium-based cemented carbide in the carbon balance is 16.25wt%, and the carbon content of Ti(C, N) in the titanium-based cemented carbide is adjusted to make the carbon content of Ti(C, N) 16.20wt%.

[0065] According to the above ratio, Ti(C, N), Co, Ni, TaC, NbC, Cr 3 C 2 , VC and Mo are mixed, and then 3wt% of molding agent paraffin is added to the mixture to obtain

[0066] Titanium-based cemented carbide mixture;

[0067] According to the above ratio, WC, Co, Ni, TaC, NbC, Cr 3 C 2 , VC and Mo are mixed, and then 3wt% of molding agent paraffin is added to the mixture to obtain a tungsten carbide cemented carbide mixture;

[0068] The titanium-based cemented carbide mixture and the tungsten carbide cemented carbide mixture are respectively loaded into different parts of the die, and then pre-pressed and cold isostatically pressed. The pre-pressing pressure is 50MPa and the cold isostatic pressing pressure is 120MPa.

[0069] Finally, the obtained green body is pressurized and sintered at a sintering pressure of 7 MPa, a sintering temperature of 1450° C., and a sintering time of 40 minutes to obtain a composite of titanium-based cemented carbide and tungsten carbide cemented carbide having a bending strength greater than or equal to 2500 MPa.

[0070] Example 4

[0071] The composite of titanium-based cemented carbide and tungsten carbide is composed of titanium-based cemented carbide and tungsten carbide; wherein the hard phase of the titanium-based cemented carbide is TiC and Ti(C, N), the hard phase content is 90wt%, the binding phase is Co and Ni, the content is 9wt%, and the balance is 1wt%, including TaC, NbC, Cr 3 C 2 The hard phase of tungsten carbide is WC, the hard phase content is 88wt%, the bonding phase is Co and Ni, the bonding phase content is 11wt%, and the balance is 1wt%, including TaC, NbC, Cr 3 C 2 ; Among them, the carbon content of tungsten carbide in the carbon balance of tungsten carbide is 6.13wt%, and the carbon content in the tungsten carbide is adjusted to make the carbon content of tungsten carbide 6.18wt%; the carbon content of TiC and Ti(C, N) in the carbon balance of titanium-based cemented carbide is 18.15wt%, and the carbon content in the titanium-based cemented carbide is adjusted to make the carbon content of TiC and Ti(C, N) 18.10wt%.

[0072] According to the above ratio, TiC, Ti(C, N), Co, Ni, TaC, NbC, Cr 3 C 2 Mixing, and then adding 4wt% of molding agent paraffin to the mixture to obtain a titanium-based hard alloy mixture;

[0073] According to the above ratio, WC, Co, Ni, TaC, NbC, Cr 3 C 2 Mixing, and then adding 4wt% of molding agent paraffin to the mixture to obtain a tungsten carbide cemented carbide mixture;

[0074] The titanium-based cemented carbide mixture and the tungsten carbide cemented carbide mixture are respectively loaded into different parts of the die, and then pre-pressed and cold isostatically pressed. The pre-pressing pressure is 60MPa and the cold isostatic pressing pressure is 150MPa.

[0075] Finally, the obtained green body is pressurized and sintered at a sintering pressure of 8 MPa, a sintering temperature of 1480° C., and a sintering time of 50 minutes to obtain a composite of titanium-based cemented carbide and tungsten carbide cemented carbide having a bending strength greater than or equal to 2400 MPa.

[0076] Example 5

[0077] The composite of titanium-based cemented carbide and tungsten carbide is composed of titanium-based cemented carbide and tungsten carbide; wherein the hard phase of the titanium-based cemented carbide is TiC, the hard phase content is 92wt%, the binding phase is Co and Ni, the content is 7wt%, and the balance is 1wt%, including TaC, NbC, Cr 3 C 2 , VC and Mo; the hard phase of tungsten carbide is WC, the hard phase content is 92wt%, the bonding phase is Co and Ni, the bonding phase content is 7wt%, and the balance is 1wt%, including TaC, NbC, Cr 3 C 2 , VC and Mo;

[0078] According to the above ratio, TiC, Co, Ni, TaC, NbC, Cr 3 C 2 , VC and Mo are mixed, and then 5wt% of molding agent rubber is added to the mixture to obtain a titanium-based hard alloy mixture;

[0079] According to the above ratio, WC, Co, Ni, TaC, NbC, Cr 3 C 2 , VC and Mo are mixed, and then 5wt% of molding agent rubber is added to the mixture to obtain a tungsten carbide cemented carbide mixture;

[0080] The titanium-based cemented carbide mixture and the tungsten carbide cemented carbide mixture are respectively loaded into different parts of the die, and then pre-pressed and cold isostatically pressed. The pre-pressing pressure is 70MPa and the cold isostatic pressing pressure is 180MPa.

[0081] Finally, the obtained green body is pressurized and sintered at a sintering pressure of 10 MPa, a sintering temperature of 1500° C., and a sintering time of 1 h to obtain a composite of titanium-based cemented carbide and tungsten carbide cemented carbide having a bending strength greater than or equal to 2200 MPa.

[0082] The above embodiments are only used to help understand the method and core idea of ​​the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0083] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A composite of titanium-based cemented carbide and tungsten carbide cemented carbide, consisting of titanium-based cemented carbide and tungsten carbide cemented carbide; Based on the mass of titanium-based cemented carbide, the hard phase of the titanium-based cemented carbide is selected from one or two of TiC and Ti(C, N), with a content of 70-96wt%, and the binding phase includes one or more of Co, Ni and Fe, with a content of 4-30wt%; Based on the mass of tungsten carbide, the hard phase of tungsten carbide is WC, the content is 70-96wt%, and the binding phase includes one or more of Co, Ni and Fe, the content is 4-30wt%; The carbon content of the alloy with high binder phase content in the composite increases by 0-0.05wt% on the basis of carbon balance, and the carbon content of the alloy with low binder phase content in the composite decreases by 0-0.05wt% on the basis of carbon balance.

2. The composite body according to claim 1, characterized in that The absolute value of the difference between the binder phase content of the titanium-based cemented carbide and the binder phase content of the tungsten carbide cemented carbide is 0 to 10 wt %.

3. The composite body according to claim 1 or 2, characterized in that: The absolute value of the difference between the binder phase content of the titanium-based cemented carbide and the binder phase content of the tungsten carbide cemented carbide is 1 to 5 wt %.

4. The composite body according to claim 1, characterized in that The titanium-based cemented carbide and / or the tungsten carbide cemented carbide further include one or more of TaC, NbC, Cr3C2, VC and Mo.

5. The composite body according to claim 1, characterized in that Based on the mass of tungsten carbide hard alloy, the content of hard phase is 85-92wt%, and the content of bonding phase is 6-18wt%; based on the mass of titanium-based hard alloy, the content of hard phase is 85-92wt%, and the content of bonding phase is 6-18wt%.

6. The method for preparing the composite according to any one of claims 1 to 5, comprising the following steps: The titanium-based cemented carbide mixture and the tungsten carbide cemented carbide mixture are placed in different areas of the preparation device, and then pressed into shape to obtain a green body; The green body is pressure-sintered to obtain a composite body.

7. The preparation method according to claim 6, characterized in that: The titanium-based cemented carbide mixture further includes a molding agent, and the molding agent is 1 to 5 wt % of the titanium-based cemented carbide mixture; And / or, the tungsten carbide cemented carbide mixture further includes a molding agent, and the molding agent is 1 to 5 wt % of the tungsten carbide cemented carbide mixture; The molding agent includes one or more of paraffin, polyethylene glycol and rubber.

8. The preparation method according to claim 6, characterized in that: The compression molding specifically includes pre-compression and cold isostatic pressing performed sequentially.

9. The preparation method according to claim 8, characterized in that: The pre-pressing pressure is 10-120 MPa, and the cold isostatic pressing pressure is 50-300 MPa.

10. The preparation method according to claim 7, characterized in that: The pressure of the pressure sintering is 1-12 MPa, the temperature is 1200-1600° C., and the time is 0.3-3 h.

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