Shaping method of silicon carbide powder particles

Abstract

The invention discloses a shaping method of silicon carbide powder particles. The method comprises: 1, mixing a soluble inorganic salt and silicon carbide raw powder, grinding, and drying to obtain a mixture; 2, making the mixture heated to the temperature above the fused salt eutectic melting temperature to obtain a melt; and 3, cooling the melt to room temperature, grinding, washing and drying to obtain shaped silicon carbide powder particles. According to the method, soluble inorganic salt is heated and subjected to heat preservation to form liquid-phase molten salt, and the liquid-phase molten salt penetrates through powder particles of silicon carbide raw powder, so that agglomeration and accumulation of the silicon carbide powder particles are prevented, sharp corners of the powder are eliminated, the silicon carbide particles gradually become spheroidized in shape, shaping of the silicon carbide powder particles is achieved, powder crushing and reunion and the introduction of impurities are avoided, the shaping effect is improved, and the product quality is ensured; the process is simple and relatively easy to control; and the shaped silicon carbide powder is regular in particle structure, smooth in surface, uniform in size and good in shaping effect.

Description

technical field [0001] The invention belongs to the technical field of silicon carbide powder, and in particular relates to a method for shaping silicon carbide powder particles. Background technique [0002] Silicon carbide is a kind of artificially synthesized carbide with strong covalent bond. It has the characteristics of good chemical stability, wear resistance and high thermal conductivity. It is a new type of engineering ceramic material that has developed rapidly in the field of materials and is widely used. . However, high-density silicon carbide ceramics are required in high-temperature, high-strength, and corrosive harsh application fields such as energy, aerospace, automobile industry, and marine engineering, so the silicon carbide powder has micro-nano particle size, high purity, and good quality. The particle shape and other requirements. However, the existing silicon carbide powder has many edges and corners, and the flakes, columns, and needles are mostly d...

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Problems solved by technology

[0004] (1) The mechanical method is a method of grinding the particles by external force to change the shape of the particles; the cost of this method is low, the process is relatively simple, the output is large, and its essence is a pulverization method. The introduction of impurity Fe and excess oxygen generally requires pickling or alkali cleaning after ball milling, which increases the pressure on environmental protection, causes great pollution and noise, and some methods require grading, so the grading effect is difficult to guarantee; even sometimes crushing occurs , the powder continues to become thinner to a certain extent, in order to reduce the specific surface energy, the particles reunite together to form agglomerated particles with a certain strength;

[0005] (2) Physicochemical method is a method of preparing powder from ions, atoms, and molecules through the formation of crystal nuclei and crystal growth through chemical reactions or phase transformations; this method has complex production processes, high costs, and low yields Due to the influence of the experimental environment and conditions, there are many errors in the experimental process, the experimental process is not easy to control, and the purity of the prepared product is low

[0006] Using mechanical methods and physical and chemical methods to shape silicon carbide powder particles has its own advantages and disadvantages, but there are also difficult problems such as adhesion, coagulation, excessive wear, easy explosion, agglomeration, and static electricity generation, and the shaping equipment is complex and energy-consuming. , high cost, plastic effect needs to be improved

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