A preparation process for a high-density tungsten-cobalt cemented carbide

Abstract

This invention discloses a preparation process for a high-density tungsten-cobalt cemented carbide, relating to the field of cemented carbide preparation technology. The process includes the following steps: S1: Batching: Tungsten carbide powder, cobalt powder, and a forming agent are precisely weighed according to a preset mass percentage and placed in a high-efficiency mixing device for pre-mixing to ensure that the components are initially and uniformly dispersed, resulting in a stable tungsten-cobalt mixture. This invention employs a multi-stage densification process involving wet ball milling, spray drying, die pressing, and cold isostatic pressing. This not only ensures that the mixture particles are sufficiently refined and uniformly dispersed, producing spherical composite powder with excellent flowability and significantly reducing internal defects in the formed blank, but also further enhances the density and uniformity of the blank through cold isostatic pressing, providing a good foundation for subsequent full densification during sintering, effectively reducing the porosity of the finished alloy and improving the overall structural stability.

Description

Technical Field

[0001] This invention relates to the field of cemented carbide preparation technology, and specifically to a preparation process for a high-density tungsten-cobalt cemented carbide. Background Technology

[0002] Tungsten-cobalt cemented carbide is a composite material prepared by powder metallurgy using tungsten carbide (WC) with high hardness and high melting point as the hard phase and cobalt (Co) with good plasticity and excellent wettability as the binder phase. This type of material has ultra-high hardness, excellent wear resistance, high compressive strength, good impact toughness and dimensional stability. It is an indispensable key basic material in modern industrial systems and is widely used in core fields such as six-sided hammers for artificially grown diamonds, ball teeth and drill bits for geological and mining drilling, high-end CNC cutting tools, die punches, and precision aerospace components. Among them, the six-sided hammers for artificially grown diamonds need to withstand extreme working conditions of high temperature above 2000℃ and high pressure of tens of thousands of megapascals for a long time. Geological and mining drilling tools need to cope with the impact, wear and corrosion of complex strata. High-end cutting tools need to meet the requirements of high speed, high precision and long life continuous machining. The above application scenarios have put forward more stringent technical indicators for the density, hardness, impact resistance, wear resistance, crystal phase uniformity and batch stability of tungsten-cobalt cemented carbide than conventional products.

[0003] Existing preparation processes mostly focus on simple optimization of a single step, mainly in the following aspects: First, the process design is fragmented, only targeting local optimization of single steps such as ball milling, forming or sintering, without constructing a full-process high-density collaborative control system from precise raw material ratio, wet ultrafine grinding, spray drying powder preparation, gradient forming, segmented sintering to full-dimensional detection. The parameters of each process lack linkage and matching, making it difficult to achieve uniform material dispersion, low-defect forming of the green body and full densification of sintering from the root. Secondly, the raw material mixing and grinding process is poorly controlled. Dry grinding easily leads to particle agglomeration and uneven dispersion. Inappropriate setting of parameters in wet grinding results in poor slurry stability and wide particle size distribution. Subsequently, the powder sphericity of spray-dried powder is low and the flowability is poor, which directly leads to defects such as pores, cracks and uneven density inside the pressed green body. Third, the molding process is simple, mostly using conventional mold pressing without combining cold isostatic pressing for secondary densification. The initial density of the blank is low and the uniformity is poor. During high-temperature sintering, uneven shrinkage, deformation, cracking and other problems are likely to occur, which greatly increases the scrap rate of finished products. Fourth, the sintering process control precision is insufficient. Conventional atmospheric pressure sintering or single temperature sintering is mostly adopted. The segmented precise temperature control and pressure protection of dewaxing, pre-firing and densification are not achieved. This easily leads to phenomena such as residual forming agent, abnormal grain growth, oxidation, and incomplete pore closure, resulting in low density, high porosity, and difficulty in achieving both hardness and toughness in the finished alloy product. Fifth, the quality testing system is incomplete, only testing conventional indicators such as hardness and density, lacking a comprehensive characterization of cobalt content distribution, crystal phase structure, grain size, and pore morphology. This makes it impossible to achieve consistent performance control between product batches, resulting in short service life, high failure risk, and large performance fluctuations of products under high-end extreme working conditions.

[0004] Therefore, it is necessary to invent a preparation process for a high-density tungsten-cobalt cemented carbide to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a preparation process for high-density tungsten-cobalt cemented carbide, in order to solve the problems in the above-mentioned technologies that lack a complete high-density synergistic system, and that optimization of only a single step leads to low density and high porosity of the finished product, making it difficult to achieve the core mechanical properties, and resulting in large batch performance fluctuations and poor stability, which cannot meet the stringent requirements for comprehensive material performance in high-end fields such as artificially grown diamonds and high-intensity drilling in geological mines.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a preparation process for a high-density tungsten-cobalt cemented carbide, comprising the following steps in sequence: S1: Ingredients: Weigh tungsten carbide powder, cobalt powder and molding agent precisely according to the preset mass percentage, place them in a high-efficiency mixing device for premixing, and ensure that each component is initially and evenly dispersed to obtain a tungsten-cobalt mixture with stable composition. S2: Ball mill grinding: The tungsten-cobalt mixture is transferred into a ball mill, and alcohol and deionized water are added as a dispersant and grinding medium. The ultrafine grinding process is adopted, and the grinding speed and time are controlled to make the mixture particles fully refined and evenly dispersed, eliminating particle agglomeration, and obtaining a slurry with uniform particle size, stable dispersion and good flowability. S3: Solid-liquid separation and spray drying: The ground slurry is subjected to preliminary solid-liquid separation through a filter press to remove excess liquid medium. Then it is fed into a pressure spray drying tower. The inlet and outlet temperatures, feed rate and atomization pressure are precisely controlled to complete deep solid-liquid separation and powder granulation, and obtain spherical composite powder with high sphericity, stable bulk density, narrow particle size distribution and excellent flowability. S4: Mold pressing and forming: The spherical composite powder is quantitatively added to a high-precision hydraulic mold and pressed. The pressing pressure and holding time are controlled to make the powder particles tightly bonded, forming a blank with a regular shape and uniform density, eliminating surface and shallow internal defects of the blank. S5: Cold Isostatic Pressing: The initial blank after being pressed by the mold is placed in a cold isostatic pressing equipment, and pressure is applied evenly in all directions using a liquid pressure transmission method to further eliminate residual pores inside the blank, improve the overall density and uniformity of the blank, and achieve gradient densification of the blank. S6: High-temperature sintering: The dense billet after cold isostatic pressing is sent into a sintering furnace, a protective gas is introduced, and a three-stage precise temperature-controlled sintering is carried out under pressure. The process of removing the forming agent, the initial bonding of particles, uniform grain growth and complete closure of pores are completed in sequence to obtain an alloy billet that is free from oxidation, free from abnormal growth and fully densified. S7: Finishing and Grinding: Grinding the sintered high-density alloy billet to control dimensional accuracy and surface roughness; S8: Finished product inspection: The cobalt content and distribution uniformity in the finished product are detected by a coercive magnetometer, the hardness of the finished product is tested according to the HRA Rockwell hardness standard, the density of the finished product is tested by the water displacement method, and the crystal phase structure, grain size and distribution of the finished product are observed by a high-magnification metallographic microscope; after passing the inspection, the high-density tungsten cobalt cemented carbide finished product is obtained.

[0007] Preferably, the raw materials in step S1 are proportioned in the following mass percentages: 92-94 wt% tungsten carbide powder; Cobalt powder 6-8 wt%; The remainder is molding agent; The cemented carbide has a density of ≥99.2%, a hardness of ≥90HRA, and a porosity of ≤0.5%, exhibiting both excellent impact resistance and wear resistance.

[0008] Preferably, the ball mill grinding in step S2 is wet grinding, with a rotation speed of 30–60 r / min and a grinding time of 12–48 h.

[0009] Preferably, in step S3, the inlet temperature of the spray drying tower is 200–320℃, the outlet temperature is 80–110℃, and the loose density of the prepared spherical composite powder is 2.8–3.5 g / cm³.

[0010] Preferably, the process parameters for mold pressing in step S4 are 100–300 MPa and the holding time is 5–30 s.

[0011] Preferably, the process parameters for cold isostatic pressing in step S5 are: static pressure of 100-300 MPa, holding time of 1-10 min, and relative density of the billet after cold isostatic pressing ≥65%.

[0012] Preferably, the process parameters for segmented sintering in step S6 are as follows: low-temperature dewaxing stage: 300-500℃, to remove the forming agent from the green body; medium-temperature pre-firing stage: 800-1100℃, to allow the material particles in the green body to initially combine; high-temperature densification stage: 1350-1480℃, holding for 20-120 minutes, sintering pressure 1-6 MPa.

[0013] Preferably, the protective gas in step S6 is argon, and the sintering furnace is a vacuum sintering furnace.

[0014] Preferably, the high-density tungsten-cobalt cemented carbide product is used to manufacture a six-sided top hammer, which is used for artificial diamond cultivation and can simulate the high-temperature and high-pressure environment inside the Earth to rapidly produce diamonds.

[0015] Preferably, the high-density tungsten-cobalt cemented carbide product is used to manufacture cemented carbide rods or drilling teeth, the rods being used for high-strength drill bits, and the teeth being used for geological and mining drilling.

[0016] The technical effects and advantages provided by the present invention in the above technical solution are as follows: 1. This invention constructs a multi-stage densification synergistic processing system. Through wet ball milling, spray drying, mold pressing and cold isostatic pressing, the mixed material particles are not only fully refined and evenly dispersed, but the prepared spherical composite powder has excellent flowability and significantly reduces the internal defects of the formed green body. Furthermore, the density and uniformity of the green body are further improved by cold isostatic pressing, which provides a good premise for subsequent full densification in sintering, effectively reduces the porosity of the alloy product and improves the overall structural stability. 2. This invention utilizes a segmented high-temperature sintering process under protective gas pressure to complete the removal of forming agent, initial particle bonding, and densification transformation in stages. Precise control of sintering parameters prevents abnormal grain growth. Simultaneously, combined with comprehensive finished product testing methods, it achieves all-round quality control of cobalt content, hardness, density, and crystal phase structure, ensuring product performance consistency and stability. Moreover, the finished product can be adapted to various high-end scenarios such as lab-grown diamonds and geological drilling, demonstrating outstanding practicality and industrial value. 3. This invention establishes a suitable mixture by adjusting the mass ratio of tungsten carbide powder and cobalt powder, along with a forming agent, to create a high-density, high-hardness alloy. Simultaneously, it strictly controls the density, hardness, and porosity of the finished product, giving the alloy both impact resistance and wear resistance. This solves the problem of traditional tungsten-cobalt cemented carbide having limited performance and difficulty adapting to harsh working conditions. It also addresses the industry pain point of traditional processes having limited performance and difficulty adapting to harsh conditions. The product can be widely used in fields such as artificially grown diamonds, geological drilling, and high-end cutting tools, combining technological advancement, economic practicality, and industrialization value, thus promoting the high-end upgrading of the tungsten-cobalt cemented carbide industry. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the process flow for preparing the high-density tungsten-cobalt cemented carbide of the present invention. Detailed Implementation

[0018] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0019] This invention provides, for example Figure 1 The preparation process of a high-density tungsten-cobalt cemented carbide shown includes the following steps in sequence: Step 1: Ingredients: Weigh the tungsten carbide powder, cobalt powder and molding agent precisely according to the preset mass percentage, and place them in a high-efficiency mixing device for premixing to ensure that the components are initially and evenly dispersed, so as to obtain a tungsten-cobalt mixture with stable composition. Step 2: Ball mill grinding: Transfer the tungsten-cobalt mixture into a ball mill, add alcohol and deionized water as a dispersant and grinding medium, and use an ultrafine grinding process to control the grinding speed and time to fully refine and evenly disperse the mixture particles, eliminate particle agglomeration, and obtain a slurry with uniform particle size, stable dispersion, and good flowability. Step 3: Solid-liquid separation and spray drying: The ground slurry is subjected to preliminary solid-liquid separation through a filter press to remove excess liquid medium. Then it is fed into a pressure spray drying tower. The inlet and outlet temperatures, feed rate and atomization pressure are precisely controlled to complete deep solid-liquid separation and powder granulation, and obtain spherical composite powder with high sphericity, stable bulk density, narrow particle size distribution and excellent flowability. Step 4: Mold pressing and forming: The spherical composite powder is quantitatively added to a high-precision hydraulic mold, and a pressing process is adopted to control the pressing pressure and holding time, so that the powder particles are tightly combined to form a blank with a regular shape and uniform density, eliminating surface and shallow internal defects of the blank. Step 5: Cold Isostatic Pressing: The initial blank pressed by the mold is placed in a cold isostatic pressing equipment, and pressure is applied evenly in all directions using a liquid pressure transmission method to further eliminate residual pores inside the blank, improve the overall density and uniformity of the blank, and achieve gradient densification of the blank. Step Six: High-Temperature Sintering: The dense billet after cold isostatic pressing is sent into a sintering furnace, a protective gas is introduced, and a three-stage precise temperature-controlled sintering is carried out under pressure. The process of removing the forming agent, the initial bonding of particles, uniform grain growth and complete closure of pores are completed in sequence to obtain an alloy billet that is free from oxidation, free from abnormal growth and fully densified. Step 7: Finishing and Grinding: Grinding is performed on the sintered high-density alloy billet to control dimensional accuracy and surface roughness; Step 8: Finished Product Inspection: The cobalt content and distribution uniformity in the finished product are detected using a coercive magnetometer, the hardness of the finished product is tested according to the HRA Rockwell hardness standard, the density of the finished product is tested using the water displacement method, and the crystal phase structure, grain size and distribution of the finished product are observed using a high-magnification metallographic microscope; after passing the inspection, the high-density tungsten-cobalt cemented carbide finished product is obtained.

[0020] This embodiment sequentially executes eight steps: ingredient preparation, ball mill grinding, solid-liquid separation and spray drying, mold pressing, cold isostatic pressing, high-temperature sintering, precision machining and grinding, and finished product inspection, to complete the preparation of high-density tungsten-cobalt cemented carbide. This forms a closed-loop preparation system encompassing raw material formulation, fine powder preparation, gradient forming for densification, controllable sintering, precision machining, and comprehensive quality control. Each step is progressive, synergistic, and has interconnected process parameters, constituting the core technology system for achieving high-density tungsten-cobalt cemented carbide preparation. Its overall synergistic effect is reflected in: starting with precise proportioning of raw materials, laying the foundation for the alloy's comprehensive performance; then, through wet ultrafine grinding and spray drying, achieving fine powder preparation of the material, from the source... The process begins by ensuring the high quality of the molding material. Subsequent steps involve mold pressing and cold isostatic pressing to achieve gradual densification of the billet, effectively reducing internal defects and providing a good foundation for full densification during sintering. The sintering process employs a segmented process under protective gas pressure to precisely control the densification transformation of the billet, avoiding problems such as oxidation and abnormal grain growth, thus achieving high densification of the alloy. Further finishing and grinding ensure the dimensional and surface accuracy of the finished product, meeting actual assembly and usage requirements. Finally, comprehensive finished product inspection allows for precise control of alloy performance, screening of qualified products, and reverse verification of the rationality of each preceding process, ensuring the consistency and stability of performance in each batch.

[0021] In step one, the raw materials are mixed in the following mass percentage ratios: 92-94 wt% tungsten carbide powder; Cobalt powder 6-8 wt%; The remainder is molding agent; The density of cemented carbide is ≥99.2%, the hardness is ≥90HRA, and the porosity is ≤0.5%, which combines excellent impact resistance and wear resistance.

[0022] In this embodiment, the ratio of tungsten carbide powder to cobalt powder is precisely defined. The high hardness of tungsten carbide ensures the wear resistance and compressive strength of the alloy, while the cobalt powder acts as a binder to enhance the alloy's toughness, achieving a synergistic balance between hardness and impact resistance. The appropriate addition of forming agent ensures the formability of the material. At the same time, through clearly defined finished product performance indicators, the process parameters throughout the entire process are constrained from the result end, ensuring that the prepared alloy meets the core requirements of high-end working conditions for high density, low porosity, and excellent comprehensive mechanical properties. This allows the alloy to stably achieve high-performance indicators of density, hardness, and porosity in subsequent wet grinding, gradient forming, and segmented pressure sintering processes, while also taking into account excellent impact resistance and wear resistance. It is perfectly suited to the stringent requirements of high-end equipment manufacturing fields such as artificially grown diamonds, geological and mining drilling, and high-end cutting tools. This is the key technological foundation for achieving high-performance, high-end, and stable production of tungsten-cobalt cemented carbide.

[0023] In step two, the ball mill grinding is a wet grinding process with a rotation speed of 30–60 r / min and a grinding time of 12–48 h. In step three, the spray drying tower has an inlet temperature of 200–320℃ and an outlet temperature of 80–110℃, resulting in a loose density of 2.8–3.5 g / cm³ for the prepared spherical composite powder. In step four, the die pressing process parameters are 100–300 MPa and a holding time of 5–30 s. In step five, the cold isostatic pressing process parameters are a static pressure of 100–300 MPa. The holding time is 1-10 min. After cold isostatic pressing, the relative density of the green body is ≥65%. The process parameters for the segmented sintering in step six are as follows: low temperature dewaxing stage: 300-500℃, to remove the forming agent from the green body; medium temperature pre-firing stage: 800-1100℃, to allow the material particles in the green body to initially combine; high temperature densification stage: 1350-1480℃, holding for 20-120 min, sintering pressure 1-6 MPa. The protective gas in step six is ​​argon, and the sintering furnace is a vacuum sintering furnace.

[0024] In this embodiment, key process parameters for wet ball milling, spray drying, die pressing, cold isostatic pressing, and segmented sintering are precisely defined and matched within specific ranges. Wet ultrafine grinding is achieved at a rotation speed of 30–60 r / min and a time of 12–48 h, ensuring uniform and stable slurry. A spray drying regime with an inlet temperature of 200–320℃ and an outlet temperature of 80–110℃ yields high-quality spherical composite powder with a bulk density of 2.8–3.5 g / cm³. Initial die forming is achieved using a pressure of 100–300 MPa and a holding pressure of 5–30 s, followed by cold isostatic pressing at 100–300 MPa for 1–10 min to achieve a relative density ≥65%. Finally, the blank is sintered in a vacuum sintering furnace under argon protection, undergoing dewaxing at 300–500℃, pre-firing at 800–110℃, and high-temperature densification and segmented sintering at 1350–1480℃, combined with a pressure of 1–6 MPa. Pressurization and holding at temperature for 20–120 minutes achieve oxidation-free, abnormal grain growth-free, and fully densified transformation of the green body. The parameters of each process are matched and progressively enhanced, forming a complete and synergistic system from particle refinement, powder preparation, green body densification to sintering densification. This effectively reduces internal defects and porosity, significantly improves density, hardness, impact resistance, and wear resistance, ensuring stable and compliant product performance and meeting the stringent requirements of high-end equipment manufacturing.

[0025] High-density tungsten-cobalt cemented carbide products are used to manufacture six-sided top hammers, which are used for artificially grown diamonds. These hammers can simulate the high-temperature and high-pressure environment inside the Earth to quickly produce diamonds. High-density tungsten-cobalt cemented carbide products are also used to manufacture cemented carbide rods or drill bits. The rods are used for high-strength drill bits, and the drill bits are used for geological and mining drilling.

[0026] The high-density tungsten-cobalt cemented carbide product prepared in this embodiment, with its high density, high hardness, low porosity, and excellent compressive strength, wear resistance, and impact resistance, can be widely used in the manufacture of high-end industrial core components. Firstly, it can be used to manufacture six-sided top hammers, which are applied in artificial diamond-growing equipment. These hammers can stably simulate the extreme high-temperature and high-pressure environment inside the Earth, remaining unbroken, undeformed, and unfailed under long-term cyclic high-pressure and high-temperature loads, ensuring efficient and high-quality diamond synthesis. Secondly, it can be used to manufacture cemented carbide rods, which can be machined into high-strength drill bits, solid milling cutters, and other precision tools. Their high hardness, high rigidity, and dimensional stability meet the requirements of high-speed, heavy-load, and high-precision cutting. Thirdly, it can be used to manufacture drill teeth, which are suitable for geological and mining drilling equipment. These teeth maintain excellent impact resistance and wear resistance under hard rock impact, strong wear, and complex geological conditions, significantly improving drilling efficiency and service life.

[0027] The above applications fully demonstrate that the alloy materials prepared by the process of this invention have stable performance, strong applicability, and outstanding industrial value. They can effectively meet the stringent requirements for high-performance tungsten-cobalt cemented carbides in fields such as high-end equipment manufacturing, superhard material synthesis, and resource exploration and development, and promote the upgrading and development of related industries towards high efficiency, long life, and low cost.

[0028] Working principle of this invention: Refer to the instruction manual appendix Figure 1 When using this invention, firstly, tungsten carbide powder, cobalt powder, and forming agent are mixed according to the specified ratio to make the raw materials initially uniform. Then, the mixture is fed into a ball mill and wet ultrafine grinding is performed using alcohol / water as the medium to obtain a uniformly dispersed slurry. The slurry is spray-dried to produce a high-flowability spherical composite powder, providing high-quality raw materials for molding. The powder is pressed into a preliminary blank by a mold, and then subjected to all-round pressure by cold isostatic pressing to significantly improve the density and uniformity of the blank. Next, the blank is sent into a vacuum sintering furnace and sintered in stages at high temperature under argon protection, successively completing dewaxing, pre-firing, and densification to obtain a high-density alloy blank. Finally, the alloy blank is precision machined and ground, and after passing multiple finished product tests, a high-density tungsten-cobalt cemented carbide finished product is obtained.

[0029] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0030] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A preparation process for a high-density tungsten-cobalt cemented carbide, characterized in that: The steps are as follows: S1: Ingredients: Weigh tungsten carbide powder, cobalt powder and molding agent precisely according to the preset mass percentage, place them in a high-efficiency mixing device for premixing, and ensure that each component is initially and evenly dispersed to obtain a tungsten-cobalt mixture with stable composition. S2: Ball mill grinding: The tungsten-cobalt mixture is transferred into a ball mill, and alcohol and deionized water are added as a dispersant and grinding medium. The ultrafine grinding process is adopted, and the grinding speed and time are controlled to make the mixture particles fully refined and evenly dispersed, eliminating particle agglomeration, and obtaining a slurry with uniform particle size, stable dispersion and good flowability. S3: Solid-liquid separation and spray drying: The ground slurry is subjected to preliminary solid-liquid separation through a filter press to remove excess liquid medium. Then it is fed into a pressure spray drying tower. The inlet and outlet temperatures, feed rate and atomization pressure are precisely controlled to complete deep solid-liquid separation and powder granulation, and obtain spherical composite powder with high sphericity, stable bulk density, narrow particle size distribution and excellent flowability. S4: Mold pressing and forming: The spherical composite powder is quantitatively added to a high-precision hydraulic mold and pressed. The pressing pressure and holding time are controlled to make the powder particles tightly bonded, forming a blank with a regular shape and uniform density, eliminating surface and shallow internal defects of the blank. S5: Cold Isostatic Pressing: The initial blank after being pressed by the mold is placed in a cold isostatic pressing equipment, and pressure is applied evenly in all directions using a liquid pressure transmission method to further eliminate residual pores inside the blank, improve the overall density and uniformity of the blank, and achieve gradient densification of the blank. S6: High-temperature sintering: The dense billet after cold isostatic pressing is sent into a sintering furnace, a protective gas is introduced, and a three-stage precise temperature-controlled sintering is carried out under pressure. The process of removing the forming agent, the initial bonding of particles, uniform grain growth and complete closure of pores are completed in sequence to obtain an alloy billet that is free from oxidation, free from abnormal growth and fully densified. S7: Finishing and Grinding: Grinding the sintered high-density alloy billet to control dimensional accuracy and surface roughness; S8: Finished product inspection: The cobalt content and distribution uniformity in the finished product are detected by a coercive magnetometer, the hardness of the finished product is tested according to the HRA Rockwell hardness standard, the density of the finished product is tested by the water displacement method, and the crystal phase structure, grain size and distribution of the finished product are observed by a high-magnification metallographic microscope; after passing the inspection, the high-density tungsten cobalt cemented carbide finished product is obtained.

2. The preparation process of a high-density tungsten-cobalt cemented carbide according to claim 1, characterized in that: In step S1, the raw materials are proportioned according to the following mass percentages: 92-94 wt% tungsten carbide powder; Cobalt powder 6-8 wt%; The remainder is molding agent; The cemented carbide has a density of ≥99.2%, a hardness of ≥90HRA, and a porosity of ≤0.5%, exhibiting both excellent impact resistance and wear resistance.

3. The preparation process of a high-density tungsten-cobalt cemented carbide according to claim 1, characterized in that: In step S2, the ball mill grinding is a wet grinding process with a rotation speed of 30–60 r / min and a grinding time of 12–48 h.

4. The preparation process of a high-density tungsten-cobalt cemented carbide according to claim 1, characterized in that: In step S3, the inlet temperature of the spray drying tower is 200–320℃, the outlet temperature is 80–110℃, and the loose density of the prepared spherical composite powder is 2.8–3.5 g / cm³.

5. The preparation process of a high-density tungsten-cobalt cemented carbide according to claim 1, characterized in that: The process parameters for mold pressing in step S4 are 100–300 MPa and holding time 5–30 s.

6. The preparation process of a high-density tungsten-cobalt cemented carbide according to claim 1, characterized in that: The process parameters for cold isostatic pressing in step S5 are: static pressure 100-300 MPa, holding time 1-10 min, and relative density of the billet after cold isostatic pressing ≥65%.

7. The preparation process of a high-density tungsten-cobalt cemented carbide according to claim 1, characterized in that: The process parameters for the segmented sintering in step S6 are as follows: low-temperature dewaxing stage: 300-500℃, to remove the forming agent from the green body; medium-temperature pre-firing stage: 800-1100℃, to allow the material particles in the green body to initially combine; high-temperature densification stage: 1350-1480℃, holding for 20-120 minutes, sintering pressure 1-6 MPa.

8. The preparation process of a high-density tungsten-cobalt cemented carbide according to claim 1, characterized in that: In step S6, the protective gas is argon, and the sintering furnace is a vacuum sintering furnace.

9. The preparation process of a high-density tungsten-cobalt cemented carbide according to claim 1, characterized in that: The high-density tungsten-cobalt cemented carbide finished product is used to manufacture a six-sided top hammer, which is used for artificial diamond cultivation and can simulate the high temperature and high pressure environment inside the Earth to quickly produce diamonds.

10. The preparation process of a high-density tungsten-cobalt cemented carbide according to claim 1, characterized in that: The high-density tungsten-cobalt cemented carbide finished product is used to manufacture cemented carbide rods or drilling teeth. The rods are used for high-strength drill bits, and the teeth are used for geological and mining drilling.

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