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CN-121974355-A - Superfine tungsten carbide material with low agglomeration rate and preparation method and application thereof

CN121974355ACN 121974355 ACN121974355 ACN 121974355ACN-121974355-A

Abstract

The invention discloses a superfine tungsten carbide material with low agglomeration rate, and a preparation method and application thereof, wherein the preparation method comprises the following steps of reducing blue tungsten by a reverse hydrogen reduction method to obtain tungsten powder; uniformly mixing tungsten powder with a carbon source and a grain inhibitor to obtain a mixture, carrying out high-temperature carbonization to obtain tungsten carbide, wherein the grain inhibitor comprises at least one of tantalum, niobium, titanium and yttrium, and carrying out crushing air current classification on the tungsten carbide to obtain the ultrafine tungsten carbide with low agglomeration rate. The superfine tungsten carbide material prepared by the invention has extremely low agglomeration rate, uniform and fine particle size, ensures the superfine grain structure of the material, and is also beneficial to improving the compactness and mechanical property of the material.

Inventors

  • XU KAIHUA
  • FENG HAO
  • SHE HAIYANG
  • Zhao Langang
  • Ma Wenpei

Assignees

  • 湖北绿钨资源循环有限公司

Dates

Publication Date
20260505
Application Date
20260120

Claims (10)

  1. 1. The preparation method of the superfine tungsten carbide material with low agglomeration rate is characterized by comprising the following steps: Reducing blue tungsten by a reverse hydrogen reduction method to obtain tungsten powder; Uniformly mixing the tungsten powder with a carbon source and a grain inhibitor to obtain a mixture, and carrying out high-temperature carbonization to obtain tungsten carbide, wherein the grain inhibitor comprises at least one of tantalum, niobium, titanium and yttrium; And carrying out crushing air current classification on the tungsten carbide to obtain the superfine tungsten carbide with low agglomeration rate.
  2. 2. The method for preparing the ultrafine tungsten carbide material with low agglomeration rate according to claim 1, wherein the oxygen index of blue tungsten is 2.94-2.97, the specific surface granularity is 10-35 um, and the loose ratio is 2.5-4.5 g/cm 3 .
  3. 3. The method for preparing the ultrafine tungsten carbide material with low agglomeration rate according to claim 1, wherein the temperature of the reverse hydrogen reduction method is divided into six-zone reduction temperatures, the specific temperature zone temperatures are that the first-zone temperature is 500-560 ℃, the second-zone temperature is 560-600 ℃, the third-zone temperature is 600-750 ℃, the fourth-zone temperature is 750-800 ℃, the fifth-zone temperature is 800-950 ℃ and the sixth-zone temperature is 950-1050 ℃.
  4. 4. The method for preparing a low agglomeration rate ultrafine tungsten carbide material according to claim 3, wherein the six-zone reduction temperature has a specific temperature of 550 ℃ in the first zone, 600 ℃ in the second zone, 720 ℃ in the third zone, 790 ℃ in the fourth zone, 900 ℃ in the fifth zone and 1020 ℃ in the sixth zone.
  5. 5. The method for preparing a low-agglomeration superfine tungsten carbide material according to claim 1, wherein the ground specific surface area of the tungsten powder is 5.0-6.0 m 3 /g.
  6. 6. The preparation method of the ultrafine tungsten carbide material with the low agglomeration rate, which is characterized in that the carbon source comprises carbon black, and the mass of the carbon source is 6-7wt% of the mass of the mixture; and/or the addition amount of the grain inhibitor is 0.7-1.5wt% of the mass of the mixture; And/or the high-temperature carbonization temperature is 1300-1550 ℃, and the high-temperature carbonization time is 10-25 min.
  7. 7. The preparation method of the ultrafine tungsten carbide material with the low agglomeration rate according to claim 1, wherein the grain inhibitor comprises 1 (0.4-0.6): 0.2-0.3): 0.05-0.1 (mass ratio of tantalum, niobium, titanium and yttrium).
  8. 8. The preparation method of the ultrafine tungsten carbide material with the low agglomeration rate according to claim 1, wherein the crushing airflow classification is specifically carried out by airflow crushing and dispersing under the conditions that the gap airflow is 200-350 m 3 /h, the grinding airflow is 450-600 m 3 /h and the rotating speed of a classification wheel is 3000-4000 rpm.
  9. 9. The low-agglomeration-rate ultrafine tungsten carbide material is characterized by being prepared by the preparation method of the low-agglomeration-rate ultrafine tungsten carbide material in any one of claims 1-8.
  10. 10. A cemented carbide characterized in that the raw material for preparation comprises the ultrafine tungsten carbide material with low agglomeration rate according to claim 9.

Description

Superfine tungsten carbide material with low agglomeration rate and preparation method and application thereof Technical Field The invention relates to the technical field of powder metallurgy, in particular to a superfine tungsten carbide material with low agglomeration rate and a preparation method and application thereof. Background In the cemented carbide industry, ultrafine tungsten carbide with a particle size of 0.2-0.5 μm becomes a core material in many high-end fields by virtue of excellent physical and chemical properties. The alloy has excellent electric and heat conductivity, extremely high hardness and high temperature environment resistance, so that the alloy plays an irreplaceable role in the scenes of high-speed cutting tools, top hammers, precise ceramic products and the like, and is praised as a key foundation stone for supporting the development of modern industry especially in the field of hard alloy. The mechanical properties of the hard alloy are closely related to the size of tungsten carbide particles, and the smaller the particles are, the more the hardness, the elastic modulus, the wear resistance, the compressive strength and the like of the alloy can be obviously improved. Although the nano-level tungsten carbide powder has better performance, the nano-level tungsten carbide powder is limited by the difficulty of production technology and high cost, and is difficult to realize large-scale industrial application at present. In contrast, the superfine tungsten carbide has good balance between performance and cost, and the cost performance advantage makes the superfine tungsten carbide a main choice for producing medium-high-end hard alloy, and plays an important role in the precision manufacturing fields of aspherical glass lens molds, water jet nozzles and the like. However, the production of ultra-fine tungsten carbide still faces significant challenges. The powder is easy to have the problems of abnormal growth and insufficient uniformity of particles in the preparation process, which directly affects the quality of the subsequent hard alloy. When the powder with poor uniformity is sintered, abnormal growth of particles is very easy to occur, coarse grains are formed, and the bending strength and heat sensitivity of the alloy are reduced; meanwhile, when the sintering temperature is increased, the powder can generate more coarse crystal defects, and the mechanical properties of the product are further reduced. In addition, for the superfine binderless phase hard alloy with the binder content lower than 0.5wt%, the raw material powder has small particle size (less than 1 mm) and the binder and grain inhibitor contents are extremely low, so that the traditional mixing process is easy to cause local agglomeration, micro air holes are formed after sintering, the material performance is seriously weakened, the product forming quality is unstable, the reworking rate is higher, and the production cost is increased. Under the background, the effect of the grain inhibitor is more critical, the grain inhibitor can effectively inhibit abnormal growth of grains of superfine tungsten carbide in the sintering process, particularly in a scene with extremely low binder content, the coarse grain problem caused by insufficient powder uniformity or fluctuation of sintering temperature can be relieved, and the generation of micro-pores is reduced, so that the mechanical property and the forming stability of the hard alloy are ensured, and the method is a core technical means for improving the quality of products and reducing the production cost. Therefore, developing a new preparation process of superfine tungsten carbide, improving the uniformity of superfine tungsten carbide powder and reducing agglomeration has important significance for realizing the preparation of high-quality fine-grain hard alloy. Disclosure of Invention In view of the technical problems in the background art, the invention provides a superfine tungsten carbide material with low agglomeration rate, and a preparation method and application thereof, and aims to solve the technical problems of insufficient uniformity and easy agglomeration of superfine tungsten carbide powder. In a first aspect, the present invention provides a method for preparing an ultrafine tungsten carbide material with a low agglomeration rate, comprising the steps of: Reducing blue tungsten by a reverse hydrogen reduction method to obtain tungsten powder; uniformly mixing tungsten powder with a carbon source and a grain inhibitor to obtain a mixture, and carrying out high-temperature carbonization to obtain tungsten carbide, wherein the grain inhibitor comprises at least one of tantalum, niobium, titanium and yttrium; crushing and air-classifying the tungsten carbide to obtain the ultrafine tungsten carbide with low agglomeration rate. Preferably, the oxygen index of blue tungsten is 2.94-2.97, the specific surface granularity is 10-35 um, and the loose