A cemented carbide material, a method for producing the same and use thereof

Abstract

The present application relates to a kind of cemented carbide materials and its preparation method and application, the cemented carbide material includes binder phase and hard phase;The hard phase includes WC skeleton and the titanium tungsten carbide phase distributed on the WC skeleton;The titanium tungsten carbide phase is core ring structure, the core ring structure includes core and the ring portion surrounding the core, and the Ti content of the core of the core ring structure is higher than the Ti content of the ring portion of the core ring structure;The cemented carbide material realizes light weight, still has high wear resistance, high corrosion resistance, high strength and high toughness simultaneously, and its density is preferably as low as 11.2g / cm 3 Below, Vickers hardness HV30 is preferably as high as 1620N / mm 2 Above, tensile strength is preferably as high as 2230MPa, porosity is better than A04;Meet the use requirement of submersible electric pump shaft sleeve under severe working condition.

Description

Technical Field

[0001] This invention relates to the field of alloy materials and their preparation technology, and in particular to a cemented carbide material, its preparation method and application. Background Technology

[0002] A submersible electric pump (SAP) is a multi-stage centrifugal pump lift system deployed deep within oil wells. It is a core piece of equipment in modern mechanical oil production (lifting crude oil from underground to the surface), particularly suitable for oil fields with high water cut and offshore oil fields. The SSP bushing is a critical component located on the drive shaft of its core rotating part. It fits on each stage of the SSP's drive shaft, primarily within the pump section, protector, and motor, serving to compensate for wear on the main shaft and to maintain the shaft's alignment. The bushing is a crucial precision component ensuring the stable operation of the SSP in harsh downhole environments. Because the SSP needs to operate continuously at temperatures of 150°C to 200°C downhole, while simultaneously enduring high-speed rotation, sand erosion, and corrosive gases, the bushing must possess extreme wear resistance, corrosion resistance, and high-temperature resistance—key to ensuring the system's stable downhole operation.

[0003] Among these factors, sand particles in the downhole fluid medium can cause severe erosion and wear on the bushing, so the bushing material must have extremely high hardness (e.g., hard alloy hardness > 90 HRA) and wear resistance; downhole media usually contain corrosive components such as hydrogen sulfide, carbon dioxide, and brine, so the bushing material needs to have stable chemical properties, with nickel-based binder phases performing particularly well in this regard; the operating temperature of the submersible pump is as high as 200℃, which requires the bushing material to maintain stable structure and no significant decrease in hardness at high temperatures, and to have a good match with the thermal expansion coefficient of the shaft; under high-speed rotation and possible impact conditions, the bushing material needs to have sufficient bending strength to prevent brittle fracture; at the same time, as a precision component, the bushing requires extremely high ① dimensional and geometric tolerance control to ensure sealing and alignment effects, which depends on the uniformity of the material and the processing technology.

[0004] Moreover, in submersible electric pumps, excessively dense bushing materials can lead to a series of serious structural, reliability, and energy consumption problems, which is particularly critical for tandem pump sets that can stretch for thousands of meters. Specifically: ① Dynamics and Vibration: High-speed rotation causes a sharp increase in centrifugal force (centrifugal force is proportional to mass), which in turn leads to changes in the system's natural frequency, easily causing resonance, intensified vibration, increased noise, and accelerated wear and failure of adjacent components such as bearings and mechanical seals; ② Bearing Load and Lifespan: Radial and axial loads increase significantly, and the heavy bushings increase the bearing load. In vertically installed multi-stage pumps, the top thrust bearing experiences enormous load pressure; bearing overheating and premature fatigue failure occur, shortening the overall fault-free operating time of the equipment and increasing maintenance frequency; ③ System Energy Consumption: Driving heavier rotating components requires greater starting torque and operating power, consuming more electrical energy, reducing system operating efficiency, and increasing electricity costs. These problems are more pronounced in off-grid or power-constrained areas; ④ Installation and Maintenance: The increased weight of a single-stage pump leads to a significant increase in the weight of the entire pump set, which can range from tens to hundreds of stages. The difficulty and risk of raising and lowering the well have increased, the requirements for hoisting equipment have become higher, and the risk of falling into the well has increased.

[0005] Traditional cemented carbides (such as YG-type) contain high-density tungsten, with a density reaching 13-15 g / cm³. 3 This is the source of its high hardness, but it also brings all the aforementioned problems, resulting in the trade-off of "weight for strength." Ceramic materials, while having low density and good wear and corrosion resistance, have low strength and poor toughness, making them prone to brittle fracture under high-speed rotation and potential impacts.

[0006] Therefore, the goal is to provide a lightweight cemented carbide material and its preparation method that possesses the advantages of high wear resistance, high strength, and high toughness of traditional cemented carbides, while also having the characteristics of low density and good corrosion resistance of ceramic materials, thereby meeting the requirements for use in submersible electric pump bushings. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention provides a cemented carbide material, its preparation method, and its application. By selecting raw materials and coordinating the control of preparation process parameters, the cemented carbide material achieves lightweight properties while also possessing high wear resistance, high corrosion resistance, high strength, and high toughness, thus meeting the requirements for use of submersible electric pump bushings under harsh operating conditions.

[0008] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a cemented carbide material comprising a binder phase and a hard phase; the hard phase comprising a WC framework and a titanium carbide tungsten phase distributed on the WC framework; the titanium carbide tungsten phase having a core-ring structure comprising a core and a ring surrounding the core, wherein the Ti content of the core is higher than the Ti content of the ring.

[0009] In the cemented carbide material of this invention, WC grains form a continuous hard phase framework, and the titanium carbide tungsten phase has a core-ring structure. Furthermore, the Ti content in the core is higher than that in the rings, which facilitates the formation of a gradient interface layer at the microscale. This structure, on the one hand, alleviates the interfacial stress caused by the difference in thermal expansion coefficients and elastic moduli between the core (Ti-rich) and the binder phase through the rings (Ti-poor), thereby improving the bonding strength of the phase interface. On the other hand, the continuous WC framework and the core-ring structure of the titanium carbide tungsten phase work synergistically to significantly improve the alloy's resistance to crack propagation while maintaining high hardness.

[0010] Preferably, the core of the core ring structure is (Ti x W 1-x Phase C, x is 0.8~0.95, for example it can be 0.8, 0.82, 0.85, 0.88, 0.9, 0.93 or 0.95, etc.

[0011] Preferably, the ring portion of the core-ring structure is (Ti y W 1-y Phase C, y is 0.5~0.7, for example it can be 0.5, 0.52, 0.55, 0.57, 0.60, 0.62, 0.65, 0.67, 0.69 or 0.7, etc.

[0012] Preferably, in the hard phase (Ti) x W 1-x C phase and (Ti) y W 1-y The volume fraction ratio of the C phase is <0.5, for example, it can be 0.49, 0.47, 0.45, 0.43, 0.4, 0.37, 0.35, 0.32 or 0.3, etc.

[0013] Preferably, the cemented carbide material comprises 5-35 wt% binder phase metal, 5-30 wt% titanium carbide tungsten, and the balance WC, by weight percentage.

[0014] Among them, 5~35wt% is the binder phase metal, for example, it can be 5wt%, 10wt%, 15wt%, 20wt%, 25wt%, 30wt% or 35wt%; 5~30wt% is titanium carbide tungsten, for example, it can be 5wt%, 10wt%, 15wt%, 20wt%, 25wt% or 30wt% or 30wt%.

[0015] Preferably, the binder phase metal includes any one or a combination of at least two of Fe, Co, or Ni, wherein typical but non-limiting combinations include combinations of Fe and Co, combinations of Fe and Ni, or combinations of Co and Ni, and preferably a combination of Co and Ni.

[0016] Preferably, the mass ratio of Co to Ni in the binder phase metal is (0.5~2):1, for example, it can be 0.5:1, 0.8:1, 1:1, 1.2:1, 1.5:1, 1.7:1 or 2:1, etc., preferably (0.8~1.2):1.

[0017] Preferably, the cemented carbide material further includes Mo2C and / or Cr3C2.

[0018] Preferably, the cemented carbide material further comprises 0.1~5wt% Mo2C and / or 0.1~5wt% Cr3C2 by weight percentage.

[0019] Among them, 0.1~5wt%Mo2C, for example, can be 0.1wt%, 0.5wt%, 1wt%, 2wt%, 3wt%, 4wt% or 5wt%; 0.1~5wt%Cr3C2, for example, can be 0.1wt%, 0.5wt%, 1wt%, 2wt%, 3wt%, 4wt% or 5wt% or 5wt%.

[0020] Preferably, the cemented carbide material further includes rare earth metals.

[0021] Preferably, the rare earth metal includes any one or a combination of at least two of Y, Ce, or La, wherein typical but non-limiting combinations include combinations of Y and Ce, combinations of Y and La, or combinations of Ce and La, etc.

[0022] Preferably, the cemented carbide material further includes 0.01 to 1 wt% rare earth metals, for example, 0.01 wt%, 0.05 wt%, 0.2 wt%, 0.4 wt%, 0.6 wt%, 0.8 wt%, or 1 wt%.

[0023] Preferably, the average particle size of the cemented carbide material is 1~5μm, for example, it can be 1μm, 2μm, 3μm, 4μm or 5μm, etc.

[0024] Preferably, the density of the cemented carbide material is 10.5~13.5 g / cm³. 3 For example, it could be 10.5 g / cm³. 3 11g / cm 3 11.5 g / cm 3 12 g / cm 3 12.5 g / cm 3 13 g / cm 3 Or 13.5 g / cm 3 wait.

[0025] Preferably, the hardness HV30 of the cemented carbide material is 1400~1800 N / mm. 2 For example, it could be 1400 N / mm 2 1500 N / mm 2 1600 N / mm 2 1700 N / mm 2 Or 1800 N / mm 2 wait.

[0026] Wherein, the hardness HV30 of the cemented carbide material refers to the Vickers hardness of the cemented carbide material under a load of 30 kgf.

[0027] Preferably, the tensile strength of the cemented carbide material is ≥2000MPa, for example, it can be 2000MPa, 2050MPa, 2100 MPa, 2150 MPa, 2200 MPa, 2250 MPa, 2300 MPa, 2350 MPa or 2400 MPa, etc.

[0028] In a second aspect, the present invention provides a method for preparing the cemented carbide material described in the first aspect, the method comprising the following steps: The raw material powder is mixed according to the formula and then subjected to ball milling, spray drying, pressing and sintering in sequence to obtain the cemented carbide material. The raw material powder includes binder phase metal powder, tungsten carbide powder, and titanium carbide tungsten powder; the sintering temperature of the sintering treatment is 1430~1500℃, for example, it can be 1430℃, 1440℃, 1450℃, 1460℃, 1470℃, 1480℃, 1490℃ or 1500℃, etc.

[0029] The preparation method of this invention achieves precise control of the titanium carbide tungsten phase core-ring structure by controlling the sintering temperature of the sintering treatment to 1430~1500℃. Specifically, if the sintering temperature is too low (below 1430℃), the driving force of liquid phase sintering is insufficient, and the (Ti,W)C particles are difficult to undergo sufficient dissolution-precipitation reaction, resulting in incomplete ring growth, insufficient interfacial bonding strength, and some particles not having enough time to develop, thus reducing the core-ring volume fraction. If the sintering temperature is too high (above 1500℃), the atomic diffusion rate is too fast, which will destroy the continuity of the WC framework on the one hand, and cause excessive homogenization diffusion of Ti elements between the core and the ring on the other hand, causing the Ti content gradient between the core and the ring to disappear, and failing to form the structure required by this invention where "the Ti content in the core is higher than that in the ring". This invention achieves a balance between the appropriate control of the liquid phase amount and the diffusion rate of W and Ti atoms by controlling the sintering temperature within the range of 1430~1500℃. That is, the liquid phase provides a channel for atomic migration, the ring part forms a Ti-poor region due to the preferential entry of W atoms, while the core part retains the original high Ti content due to the limitation of diffusion distance, and finally forms an ideal core-ring structure with compositional gradient, thereby significantly optimizing the comprehensive mechanical properties of the material.

[0030] Preferably, the binder phase metal powder includes any one or a combination of at least two of iron powder, cobalt powder, or nickel powder, wherein typical but non-limiting combinations include combinations of iron powder and cobalt powder, combinations of iron powder and nickel powder, or combinations of cobalt powder and nickel powder, and preferably a combination of cobalt powder and nickel powder.

[0031] Preferably, the cobalt powder comprises spherical cobalt powder.

[0032] Preferably, the average particle size of the cobalt powder is 0.8~1.5μm, for example, it can be 0.8μm, 0.9μm, 1.0μm, 1.1μm, 1.2μm, 1.3μm, 1.4μm or 1.5μm, etc.

[0033] Preferably, the nickel powder includes nickel hydroxyl powder.

[0034] Preferably, the average particle size of the nickel powder is 1.5~3.5μm, for example, it can be 1.5μm, 1.8μm, 2.0μm, 2.2μm, 2.5μm, 2.8μm, 3.0μm, 3.2μm or 3.5μm.

[0035] Preferably, the mass ratio of the cobalt powder to the nickel powder is (0.5~2):1, for example, it can be 0.5:1, 0.8:1, 1:1, 1.2:1, 1.5:1, 1.8:1 or 2:1, etc., preferably (0.8~1.2):1.

[0036] Preferably, the average particle size of the tungsten carbide powder is 0.8~6.0μm, for example, it can be 0.8μm, 1.0μm, 1.5μm, 2.0μm, 2.5μm, 3.0μm, 3.5μm, 4.0μm, 4.5μm, 5.0μm, 5.5μm or 6.0μm, etc.

[0037] Preferably, the average particle size of the titanium carbide tungsten powder is 0.5~2μm, for example, it can be 0.5μm, 0.6μm, 0.8μm, 1.0μm, 1.2μm, 1.5μm, 1.8μm or 2μm, etc.

[0038] Preferably, the titanium carbide tungsten powder comprises 39.5~56.0 wt% Ti, 28.3~47.5 wt% W, and 12.5~16 wt% C.

[0039] Among them, 39.5~56.0wt% Ti, for example, can be 39.5wt%, 42.0wt%, 45.5wt%, 50.0wt%, 53.0wt%, 55.5wt%, or 56wt%, etc.; 28.3~47.5wt% W, for example, can be 28.3wt%, 30.0wt%, 32.0wt%, 35.5wt%, 40.0wt%, 43.0wt%, 45.5wt%, or 47.5wt%, etc.; 12.5~16.0wt% C, for example, can be 12.5wt%, 13.0wt%, 13.5wt%, 14.0wt%, 14.5wt%, 15.0wt%, 15.5wt%, or 16.0wt%, etc.

[0040] It should be noted that the carbon content in the titanium carbide tungsten powder is one of the key factors affecting the formation of the core-ring structure. This factor affects the directional diffusion of Ti to the core and W to the ring. Moreover, the more titanium carbide tungsten powder is added, the higher the volume fraction of the titanium carbide tungsten phase in the final core-ring structure.

[0041] Preferably, the mass ratio of Ti to W in the titanium carbide tungsten powder is (0.8~2):1, for example, it can be 0.8:1, 0.88:1, 1:1, 1.2:1, 1.4:1, 1.6:1, 1.8:1 or 2:1, etc., and preferably (1.0~1.5):1.

[0042] It should be noted that the mass ratio of Ti to W in the titanium carbide tungsten powder in the various preparation methods of the present invention is one of the key parameters. This ratio determines the initial Ti content of the core, and thus affects the compositional gradient and metallographic contrast between the core and the ring.

[0043] Preferably, the raw material powder further includes molybdenum carbide powder and / or chromium carbide powder.

[0044] Preferably, the average particle size of the molybdenum carbide powder is 0.8~2.0μm, for example, it can be 0.8μm, 0.9μm, 1.0μm, 1.2μm, 1.4μm, 1.6μm, 1.8μm or 2.0μm, etc.

[0045] Preferably, the average particle size of the chromium carbide powder is 0.5~2.0μm, for example, it can be 0.5μm, 0.6μm, 0.8μm, 1.0μm, 1.2μm, 1.4μm, 1.6μm, 1.8μm or 2.0μm.

[0046] Preferably, the raw material powder further includes rare earth powder.

[0047] Preferably, the average particle size of the rare earth powder is 1~10μm, for example, it can be 1μm, 2μm, 4μm, 6μm, 8μm or 10μm, etc.

[0048] Preferably, the rare earth powder includes any one or a combination of at least two of Y, Ce, or La, wherein typical but non-limiting combinations include combinations of Y and Ce, combinations of Y and La, or combinations of Ce and La, etc.

[0049] Preferably, the ball milling process includes wet ball milling.

[0050] Preferably, the medium used in the wet ball milling includes any one or a combination of at least two of ethanol, acetone, or hexane, wherein typical but non-limiting combinations include combinations of ethanol and acetone or combinations of ethanol and hexane, etc.

[0051] Preferably, the ball-to-material ratio in the wet ball milling is (3~5):1, for example, it can be 3:1, 3.5:1, 4:1, 4.5:1 or 5:1, etc.

[0052] Preferably, the ratio of media to mixed raw materials during wet ball milling is (200~300) mL / kg, for example, it can be 200 mL / kg, 220 mL / kg, 250 mL / kg, 270 mL / kg or 300 mL / kg, etc.

[0053] Preferably, the rotational speed of the wet ball mill is 70~130 r / min, for example, it can be 70 r / min, 80 r / min, 90 r / min, 100 r / min, 110 r / min, 120 r / min or 130 r / min, etc.

[0054] Preferably, the wet ball milling time is 30-60 hours, for example, 30 hours, 35 hours, 40 hours, 50 hours or 60 hours.

[0055] Preferably, the preparation method further includes adding a molding agent to the mixed raw materials during the ball milling process.

[0056] Preferably, based on the total mass of the mixed raw materials as 100wt%, the amount of the molding agent added is 1.5~2.5wt%, for example, it can be 1.5wt%, 1.6wt%, 1.8wt%, 2.0wt%, 2.2wt%, 2.4wt%, or 2.5wt%, etc.

[0057] Preferably, the molding agent comprises any one or a combination of at least two of paraffin, polyethylene glycol, or rubber, wherein typical but non-limiting combinations include combinations of paraffin and rubber or combinations of paraffin and polyethylene glycol, etc.

[0058] Preferably, the inlet air temperature for the spray drying is 160~220℃, for example, it can be 160℃, 170℃, 180℃, 190℃, 200℃, 210℃ or 220℃, etc.

[0059] Preferably, the outlet air temperature of the spray dryer is 90~100℃, for example, it can be 92, 94, 95, 96, 98℃, etc.

[0060] Preferably, the feed rate of the spray dryer is 30~70L / h, for example, it can be 30L / h, 40L / h, 50L / h, 55L / h, 60L / h or 70L / h.

[0061] Preferably, the atomization pressure of the spray drying is 1~1.5MPa, for example, it can be 1MPa, 1.1MPa, 1.2MPa, 1.3MPa, 1.4MPa or 1.5MPa, etc.

[0062] Preferably, the spray drying yields a granular mixture, and the particle size D50 of the granular mixture is 50~150μm, for example, it can be 50μm, 60μm, 75μm, 80μm, 100μm, 120μm, 130μm, 140μm or 150μm, etc., preferably 70~110μm.

[0063] Preferably, the pressure used in the compression molding is 120~130MPa, for example, it can be 120MPa, 123MPa, 125MPa, 128MPa or 130MPa.

[0064] Preferably, the pressing time is 8 to 20 seconds, for example, 8 seconds, 12 seconds, 15 seconds, 18 seconds, or 20 seconds.

[0065] Preferably, the sintering process is carried out in a protective gas atmosphere.

[0066] Preferably, the protective gas atmosphere includes nitrogen and / or argon.

[0067] Preferably, the sintering pressure is 3~9MPa, for example, it can be 3MPa, 4MPa, 5MPa, 6MPa, 7MPa, 8MPa or 9MPa.

[0068] Preferably, the holding time for the sintering treatment is 1 to 2 hours, for example, 1 hour, 1.2 hours, 1.5 hours, 1.8 hours, or 2 hours.

[0069] Thirdly, the present invention provides an application of the cemented carbide material described in the first aspect, wherein the cemented carbide material is used as a raw material for the bushing of a submersible electric pump.

[0070] The cemented carbide material described in this invention, with its advantages of high hardness, high tensile strength, excellent porosity, and low density, is widely used as the raw material for submersible electric pump bushings. It meets the requirements of submersible electric pump bushings for extreme wear resistance and corrosion resistance under harsh working conditions, and avoids structural, reliability, and energy consumption problems caused by the high density of the bushing in submersible electric pumps.

[0071] Compared with the prior art, the present invention has at least the following beneficial effects: (1) The cemented carbide material provided by the present invention has a continuous hard phase framework formed by WC grains, and the high-titanium, low-tungsten titanium carbide phase in the titanium carbide-tungsten phase is surrounded by the low-titanium, high-tungsten titanium carbide-tungsten phase, forming a core-ring structure. This gives it advantages such as high hardness, high tensile strength and high toughness, while achieving lightweight, i.e., low density, preferably as low as 11.2 g / cm³. 3 Below, the Vickers hardness HV30 is preferably as high as 1620 N / mm. 2 The above-mentioned tensile strength is preferably as high as 2230MPa, and the porosity is better than A04.

[0072] (2) The preparation method of cemented carbide material provided by the present invention, through the design and selection of raw material composition, combined with specific preparation process and parameters, works synergistically to prepare lightweight cemented carbide material, which has mechanical advantages such as high hardness, high tensile strength and high toughness. Moreover, the raw materials of the preparation method are readily available, the operation is simple, the cost is low, and it is easy to mass-produce on a large scale.

[0073] (3) The application of the cemented carbide material provided by the present invention, wherein the cemented carbide material is used as a raw material for the bushing of the submersible electric pump. With its advantages of high hardness, high tensile strength and excellent porosity, it meets the requirements of the submersible electric pump bushing for extreme wear resistance and corrosion resistance under harsh working conditions. Moreover, its low density avoids the structural, reliability and energy consumption problems caused by the high density of the bushing in the submersible electric pump. Attached Figure Description

[0074] Figure 1 This is a SEM image of the cemented carbide material provided in Embodiment 1 of the present invention. Detailed Implementation

[0075] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0076] I. Implementation Examples Example 1 This embodiment provides a cemented carbide material, which includes a binder phase and a hard phase; the binder phase includes Co and Ni; the hard phase includes a WC framework and a titanium carbide tungsten phase distributed on the WC framework; the titanium carbide tungsten phase has a core-ring structure, the core-ring structure includes a core and a ring surrounding the core, and the core of the core-ring structure is (Ti) x W 1-x The C phase, where 0.8 ≤ x ≤ 0.95, and the ring portion of the core ring structure is (Ti y W 1-y Phase C, where 0.5 ≤ y ≤ 0.7, (Ti x W 1-x C phase and (Ti) y W 1-y The volume fraction of the C phase is 0.45; The cemented carbide material comprises 7wt% Co, 6wt% Ni, 20wt% titanium carbide tungsten and the balance WC; the average particle size of the cemented carbide material is 4μm.

[0077] like Figure 1 As shown, this is a SEM image of the cemented carbide material described in this embodiment. It can be seen that WC grains form a continuous hard phase framework, and the γ phase (titanium carbide tungsten phase, i.e., the black γ1 phase and the gray γ2 phase in the image) is dispersed. The black γ1 phase is characterized by a high Ti content and a low W content (Ti...). x W 1-x C phase; gray γ2 phase is characterized by low Ti content and high W content (Ti y W 1-y C phase. The black γ1 phase and gray γ2 phase mentioned above refer to the phase contrast of the corresponding materials in backscattered electron mode photographs.

[0078] This embodiment also provides a method for preparing the above-mentioned cemented carbide material, the method comprising the following steps: According to the formula, Co powder (spherical cobalt powder, average particle size 1.2 μm), Ni powder (nickel hydroxyl powder, average particle size 2.2 μm), tungsten carbide powder (average particle size 1.5 μm), and titanium carbide tungsten powder (average particle size 1.5 μm, including 50.0 wt% Ti, 37.5 wt% W, and 12.5 wt% W) are mixed. C) Mix with 2wt% paraffin for 3 hours to obtain a premix; then perform wet ball milling with ethanol as the medium (ethanol to premix ratio is 250mL / Kg), ball-to-material ratio is 4:1, rotation speed is 90r / min, and milling time is 42 hours to obtain a mixed slurry. The slurry is then discharged and filtered through a 325-mesh sieve. The filtered mixed slurry is then spray-dried at an inlet air temperature of 180℃, an outlet air temperature of 96℃, a feed rate of 50L / h, and an atomization pressure of 1.2MPa to obtain a granular mixture (particle size D50 is 80μm); subsequently, the granular mixture is loaded into a mold (20 mm (length) × 15 mm (width)) and pressed (unidirectional pressing, pressure 125MPa) for 15 seconds to obtain an alloy green blank (20 mm (length) × 15 mm). mm (width); then the alloy green billet is sintered in an argon atmosphere at a pressure of 5 MPa, heated to 1450°C and held for sintering for 1.5 h, and then naturally cooled to room temperature (25°C) in the furnace to obtain the cemented carbide material.

[0079] Example 2 This embodiment provides a cemented carbide material, which includes a binder phase and a hard phase; the binder phase includes Ni; the hard phase includes a WC framework and a titanium carbide tungsten phase distributed on the WC framework; the titanium carbide tungsten phase has a core-ring structure, the core-ring structure includes a core and a ring surrounding the core, and the core of the core-ring structure is (Ti) x W 1-x The C phase, where 0.8 ≤ x ≤ 0.95, and the ring portion of the core ring structure is (Ti y W 1-y Phase C, where 0.5 ≤ y ≤ 0.7, (Ti x W 1-x C phase and (Ti) y W 1-y The volume fraction of the C phase is 0.4; The cemented carbide material comprises 12wt% Ni, 20wt% titanium carbide tungsten, and the balance WC; the average particle size of the cemented carbide material is 3μm.

[0080] This embodiment also provides a method for preparing the above-mentioned cemented carbide material, the method comprising the following steps: According to the formula, Ni powder (nickel hydroxyl powder, average particle size 1.5 μm), tungsten carbide powder (average particle size 0.8 μm), titanium carbide tungsten powder (average particle size 0.8 μm, including 45.6 wt% Ti, 39.0 wt% W and 15.4 wt% C) and 2 wt% paraffin were mixed for 3 h to obtain a premix. Then, wet ball milling was performed using ethanol as the medium (ethanol to premix ratio 250 mL / Kg), ball-to-material ratio 5:1, rotation speed 100 r / min, and milling time 50 h to obtain a mixed slurry. The slurry was discharged and filtered through a 325 mesh sieve. Subsequently, the filtered mixed slurry was spray-dried at an inlet air temperature of 190℃, an outlet air temperature of 98℃, a feed rate of 50 L / h, and an atomization pressure of 1.3 MPa to obtain a granular mixture (particle size D50 of 70 μm). The granular mixture was then loaded into a mold (20 mm (length) × 15 mm). The alloy blank (20mm (length) × 15mm (width) × 9mm (thickness)) is pressed (unidirectional pressing, pressure of 125MPa) for 15s to obtain an alloy green blank (20mm (length) × 15mm (width) × 9mm (thickness)); then the alloy green blank is sintered in an argon atmosphere at a pressure of 9MPa, heated to 1430℃ and held for sintering for 1.5h, and then naturally cooled to room temperature (25℃) in the furnace to obtain the cemented carbide material.

[0081] Example 3 This embodiment provides a cemented carbide material, which includes a binder phase and a hard phase; the binder phase includes Co and Ni; the hard phase includes a WC framework and a titanium carbide tungsten phase distributed on the WC framework; the titanium carbide tungsten phase has a core-ring structure, the core-ring structure includes a core and a ring surrounding the core, and the core of the core-ring structure is (Ti) x W 1-x The C phase, where 0.8 ≤ x ≤ 0.95, and the ring portion of the core ring structure is (Ti y W 1-y Phase C, where 0.5 ≤ y ≤ 0.7, (Ti x W 1-x C phase and (Ti) y W 1-y The volume fraction ratio of the C phase is 0.49; The cemented carbide material comprises 6wt% Co, 5wt% Ni, 20wt% titanium carbide tungsten, and 0.5wt% Mo2C, with the balance being WC; the average particle size of the cemented carbide material is 5μm.

[0082] This embodiment also provides a method for preparing the above-mentioned cemented carbide material, the method comprising the following steps: According to the formula, Co powder (spherical cobalt powder, average particle size 1.2 μm), Ni powder (nickel hydroxyl powder, average particle size 3 μm), tungsten carbide powder (average particle size 5 μm), and titanium carbide tungsten powder (average particle size 1.8 μm, including 44 wt% Ti, 40 wt% W, and 16.0 wt% W) are mixed together. C) Molybdenum carbide powder (average particle size 1μm) and 2wt% paraffin wax were mixed for 3h to obtain a premix; then, wet ball milling was performed using ethanol as the medium (ethanol to premix ratio 200mL / Kg), ball-to-material ratio 3:1, rotation speed 80r / min, and milling time 36h to obtain a mixed slurry. The slurry was discharged and filtered through a 325-mesh sieve, and then spray-dried with an inlet air temperature of 170℃, an outlet air temperature of 94℃, a feed rate of 45L / h, and an atomization pressure of 1.1MPa to obtain a granular mixture (particle size D50 of 100μm); then, the granular mixture was loaded into a mold (20 mm (length) × 15 mm). The alloy blank (20mm (length) × 15mm (width) × 9mm (thickness)) is pressed (unidirectional pressing, pressure of 125MPa) for 15s to obtain an alloy green blank (20mm (length) × 15mm (width) × 9mm (thickness)); then the alloy green blank is sintered in an argon atmosphere at a pressure of 3MPa, heated to 1500℃ and held for sintering for 1.5h, and then naturally cooled to room temperature (25℃) in the furnace to obtain the cemented carbide material.

[0083] Example 4 This embodiment provides a cemented carbide material, which further includes 0.5wt% Y (with an average particle size of 5μm). Except for the reduction and adjustment of the amount of tungsten carbide powder in the raw material powder in the preparation method, the rest is the same as in Example 1.

[0084] Example 5 This embodiment provides a cemented carbide material. Except for the mass ratio of Co to Ni being 2:1 and the preparation method being adjusted accordingly to adjust the mass ratio of Co powder to Ni powder, the cemented carbide material is the same as in Embodiment 1.

[0085] Example 6 This embodiment provides a cemented carbide material. Except for the mass ratio of Co to Ni being 0.5:1 and the preparation method being adjusted accordingly to adjust the mass ratio of Co powder to Ni powder, the cemented carbide material is the same as in Embodiment 1.

[0086] Example 7 This embodiment provides a method for preparing a cemented carbide material. Except for the mass ratio of Ti to W in the tungsten carbide powder being 1.8:1, the preparation method is the same as in Example 1.

[0087] Example 8 This embodiment provides a method for preparing a cemented carbide material. The preparation method is the same as in Example 1, except that the mass ratio of Ti to W in the tungsten carbide powder is 0.8:1.

[0088] Example 9 This embodiment provides a method for preparing cemented carbide material. The preparation method is the same as in Example 1, except that the particle size D50 of the spray-dried granular mixture is 60 μm, that is, the inlet air temperature is adjusted to 200℃, the outlet air temperature is 98℃, the feed rate is 60 L / h, and the atomization pressure is 1.4 MPa.

[0089] Example 10 This embodiment provides a method for preparing a cemented carbide material. The preparation method is the same as in Example 1, except that the particle size D50 of the spray-dried granular mixture is 140 μm, that is, the inlet air temperature is adjusted to 160℃, the outlet air temperature is 92℃, the feed rate is 40L / h, and the atomization pressure is 1.1MPa.

[0090] II. Comparative Example Comparative Example 1 This comparative example provides a cemented carbide material, which is identical to Example 1 except that the structure of the titanium carbide tungsten phase is a uniform solid solution structure (without core ring characteristics).

[0091] This comparative example provides a method for preparing the above-mentioned cemented carbide material. Except for the sintering temperature of 1400°C, the preparation method is the same as that in Example 1.

[0092] Because the sintering temperature of this comparative example was relatively low (1400℃), outside the 1430~1500℃ range, the amount of liquid phase generated at 1400℃ was insufficient, limiting the atomic diffusion rate. This resulted in the titanium carbide tungsten phase failing to form a complete core-ring structure, instead forming a discontinuous transitional structure at the ring portion. Specifically, only a portion of the particle surface was covered by the Ti-depleted ring portion, with a larger area in direct contact between the core and the binder phase, leading to insufficient interfacial bonding strength and an inability to effectively alleviate thermal stress. Therefore, the mechanical properties (such as bending strength) of the cemented carbide material obtained in this comparative example were lower than those in Example 1.

[0093] Comparative Example 2 This comparative example provides a cemented carbide material, which is identical to Example 1 except that the structure of the titanium carbide tungsten phase is a uniform (Ti,W)C solid solution structure.

[0094] This comparative example provides a method for preparing the above-mentioned cemented carbide material. Except for the sintering temperature of 1520°C, the preparation method is the same as that in Example 1.

[0095] Compared to Example 1, this comparative example, due to its higher sintering temperature (1520°C), resulted in an excessive amount of liquid phase at this overheating temperature, leading to partial dissolution of the WC framework. Simultaneously, the diffusion rates of Ti and W atoms were too rapid, resulting in homogenization of the composition. Therefore, the titanium carbide tungsten phase could not form the ideal core-ring structure with a higher Ti content in the core, instead forming a homogeneous (Ti,W)C solid solution structure. Due to the lack of a gradient interface layer to alleviate thermal stress, the interfacial bonding strength between the hard phase and the binder phase decreased, and the continuity of the WC framework was impaired. Consequently, the mechanical properties (such as hardness and flexural strength) of the cemented carbide material obtained in this comparative example were lower than those in Example 1.

[0096] III. Tests and Results The density, Vickers hardness, tensile strength, and porosity of the cemented carbide materials obtained in the above embodiments or comparative examples were tested. The test standards and methods are as follows: The density test was conducted according to GB / T 3850 standard; the Vickers hardness test was conducted according to GB / T 7997 standard; and the tensile strength test was conducted according to GB / T 3851 standard. Porosity testing was conducted according to GB / T 3488 standard (where A02 B00C00 indicates that Class A porosity (<10μm) reaches the A02 standard spectrum level, with no Class B porosity (10~25μm) and no graphite inclusions; A04B00C00 indicates that Class A porosity (<10 μm) reaches the A04 standard spectrum level (more porosity than A02 level, with no Class B porosity (10~25μm) and no graphite inclusions; A02B00C02 indicates that Class A porosity (<10 μm) reaches the A02 level, with no Class B porosity (10~25μm), graphite inclusions are present, and it reaches the C02 standard spectrum level)). The test results are shown in Table 1. Table 1 The data in Table 1 shows that: (1) As can be seen from Examples 1 to 3, the present invention achieves the preparation of lightweight cemented carbide materials by designing and selecting the composition and preparation process parameters of the cemented carbide materials. While meeting the requirements of low density, it also has high hardness, high tensile strength and excellent porosity, with a density as low as 11.2 g / cm³. 3 Below, the Vickers hardness HV30 reaches as high as 1620 N / mm. 2 The above materials have a tensile strength of over 2230MPa and a porosity superior to A04, providing high-quality raw materials for submersible electric pump shaft sleeves.

[0097] (2) As can be seen from the combined examples 1 and 4, since the cemented carbide material described in example 4 also includes rare earth element Y, during the liquid phase sintering process, rare earth Y regulates the diffusion behavior of Ti and W atoms, optimizes the core-ring structure of the titanium carbide tungsten phase, makes the composition gradient between the core and the ring more reasonable, alleviates the stress concentration at the interface, and further improves the overall performance of the cemented carbide material.

[0098] (3) As can be seen from the combined examples 1 and 5 to 10, the present invention further optimizes the mass ratio of Co to Ni in the binder phase to (0.8~1.2):1, or further optimizes the mass ratio of Ti to W in the titanium carbide tungsten powder to (1.0~1.5):1, so that the composition gradient of the core and ring of the titanium carbide tungsten phase in the obtained cemented carbide material is more reasonable and the interfacial bonding strength is further improved, thereby further improving its physical and mechanical properties; the present invention further optimizes the process parameters of the spray drying so that the particle size D50 of the obtained granular mixture is 70~110μm, which further improves the uniformity of the pressed green density and the sintering densification behavior of the obtained cemented carbide material.

[0099] (4) As can be seen from the combined examples 1 and 2, the sintering temperature of the sintering treatment described in Comparative Example 1 is too low, resulting in insufficient liquid phase generation and limited atomic diffusion. The titanium carbide tungsten phase cannot form a complete core-ring structure, but only a discontinuous transition structure at the ring part. Consequently, the interfacial bonding strength between the hard phase and the binder phase is insufficient, and the densification degree and bending strength of the alloy are significantly reduced. The sintering temperature of the sintering treatment described in Comparative Example 2 is too high, resulting in excessive liquid phase. The WC skeleton partially dissolves, and the excessive diffusion of Ti and W atoms causes homogenization of the composition, resulting in the formation of the titanium carbide tungsten phase. The uniform solid solution structure or reverse gradient structure leads to the inability to effectively alleviate interfacial stress, damage to the continuity of the WC skeleton, and simultaneous deterioration of alloy hardness and strength. This invention selects the sintering temperature of the sintering treatment as 1430~1500℃, so that the titanium carbide tungsten phase in the resulting cemented carbide material forms a complete core-ring structure with a higher Ti content in the core than in the ring, obtaining a gradient interfacial layer to alleviate thermal stress, while maintaining the continuity of the WC skeleton. As a result, it has high hardness, high tensile strength and excellent porosity, while having a low density, thus meeting the harsh working conditions of the submersible electric pump shaft sleeve.

[0100] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A cemented carbide material, characterized in that, The cemented carbide material includes a binder phase and a hard phase; the hard phase includes a WC framework and a titanium carbide tungsten phase distributed on the WC framework; the titanium carbide tungsten phase has a core-ring structure, the core-ring structure includes a core and a ring surrounding the core, and the Ti content of the core is higher than the Ti content of the ring.

2. The cemented carbide material according to claim 1, characterized in that, The core of the core-ring structure is (Ti) x W 1-x Phase C, x is 0.8~0.95; Preferably, the ring portion of the core-ring structure is (Ti y W 1-y Phase C, y is 0.5~0.7; Preferably, in the hard phase (Ti) x W 1-x C phase and (Ti) y W 1-y The volume fraction ratio of the C phase is <0.

5.

3. The cemented carbide material according to claim 1 or 2, characterized in that, The cemented carbide material comprises 5-35 wt% binder phase metal, 5-30 wt% titanium carbide tungsten, and the balance WC, by weight percentage. Preferably, the binder phase metal comprises any one or a combination of at least two of Fe, Co, or Ni, and more preferably a combination of Co and Ni; Preferably, the mass ratio of Co to Ni in the binder phase metal is (0.5~2):1, more preferably (0.8~1.2):

1.

4. The cemented carbide material according to any one of claims 1 to 3, characterized in that, The cemented carbide material also includes Mo2C and / or Cr3C2; Preferably, the cemented carbide material further comprises 0.1~5wt% Mo2C and / or 0.1~5wt% Cr3C2 by weight percentage; Preferably, the cemented carbide material further includes rare earth metals; Preferably, the rare earth metal includes any one or a combination of at least two of Y, Ce, or La; Preferably, the cemented carbide material further includes 0.01~1wt% rare earth metals by weight percentage.

5. The cemented carbide material according to any one of claims 1 to 4, characterized in that, The average particle size of the cemented carbide material is 1~5μm; Preferably, the density of the cemented carbide material is 10.5~13.5 g / cm³. 3 ; Preferably, the hardness HV30 of the cemented carbide material is 1400~1800 N / mm. 2 ; Preferably, the tensile strength of the cemented carbide material is ≥2000MPa.

6. A method for preparing a cemented carbide material according to any one of claims 1 to 5, characterized in that, The preparation method includes the following steps: The raw material powder is mixed according to the formula and then subjected to ball milling, spray drying, pressing and sintering in sequence to obtain the cemented carbide material. The raw material powder includes binder phase metal powder, tungsten carbide powder, and titanium carbide tungsten powder; the sintering temperature of the sintering treatment is 1430~1500℃.

7. The preparation method according to claim 6, characterized in that, The binder phase metal powder includes any one or a combination of at least two of iron powder, cobalt powder or nickel powder, preferably a combination of cobalt powder and nickel powder; Preferably, the cobalt powder comprises spherical cobalt powder; Preferably, the cobalt powder has an average particle size of 0.8~1.5μm; Preferably, the nickel powder includes nickel hydroxyl powder; Preferably, the average particle size of the nickel powder is 1.5~3.5μm; Preferably, the mass ratio of the cobalt powder to the nickel powder is (0.5~2):1, more preferably (0.8~1.2):1; Preferably, the tungsten carbide powder has an average particle size of 0.8~6.0 μm; Preferably, the average particle size of the titanium carbide tungsten powder is 0.5~2.0 μm; Preferably, the titanium carbide tungsten powder comprises 39.5~56.0 wt% Ti, 28.3~47.5 wt% W, and 12.5~16.0 wt% C; Preferably, the mass ratio of Ti to W in the titanium carbide tungsten powder is (0.8~2):1, more preferably (1.0~1.5):1; Preferably, the raw material powder further includes molybdenum carbide powder and / or chromium carbide powder; Preferably, the molybdenum carbide powder has an average particle size of 0.8~2.0 μm; Preferably, the average particle size of the chromium carbide powder is 0.5~2.0 μm; Preferably, the raw material powder further includes rare earth powder; Preferably, the rare earth powder has an average particle size of 1~10μm; Preferably, the rare earth powder includes any one or a combination of at least two of Y, Ce, or La.

8. The preparation method according to claim 6 or 7, characterized in that, The ball milling process includes wet ball milling; Preferably, the medium used in the wet ball milling includes any one or a combination of at least two of ethanol, acetone, or hexane; Preferably, the ball-to-material ratio in the wet ball milling is (3~5):1; Preferably, the ratio of media to mixed raw materials during wet ball milling is (200~300) mL / kg; Preferably, the rotational speed of the wet ball mill is 70~130 r / min; Preferably, the wet ball milling time is 30-60 hours; Preferably, the preparation method further includes adding a forming agent to the mixed raw materials during the ball milling process; Preferably, based on a total mass of 100 wt% of the mixed raw materials, the amount of the molding agent added is 1.5~2.5 wt%; Preferably, the molding agent comprises any one or a combination of at least two of paraffin, polyethylene glycol, or rubber.

9. The preparation method according to any one of claims 6 to 8, characterized in that, The inlet air temperature for the spray drying is 160~220℃; Preferably, the outlet air temperature of the spray dryer is 90~100℃; Preferably, the feed rate for the spray dryer is 30-70 L / h; Preferably, the atomization pressure of the spray drying is 1~1.5MPa; Preferably, the spray drying yields a granular mixture, and the particle size D50 of the granular mixture is 50~150μm, preferably 70~110μm; Preferably, the pressure used in the compression molding is 120~130MPa; Preferably, the pressing time is 8-20 seconds; preferably, the sintering process is carried out in a protective gas atmosphere. Preferably, the protective gas atmosphere includes nitrogen and / or argon; Preferably, the pressure of the sintering treatment is 3~9 MPa; Preferably, the holding time for the sintering treatment is 1 to 2 hours.

10. An application of the cemented carbide material according to any one of claims 1 to 5, characterized in that, The cemented carbide material is used as the raw material for the submersible electric pump bushing.

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