Normal-pressure solid-phase sintered silicon carbide ceramic profiled part and manufacture method thereof

Abstract

The invention discloses a normal-pressure solid-phase sintered silicon carbide ceramic profiled part and a manufacture method thereof. A compact silicon carbide ceramic profiled part product is obtained by material preparation, material mixing through ball milling, high pressure grouting, drying in shade and low temperature drying and high temperature sintering. Through optimized matching of silicon carbide particles at different levels and effective design of channels of a resin die, micrometer powder is introduced to overcome obstruction of die channels, thereby obviously prolonging the service life of the die. The micrometer powder is large in size and small in specific surface area, thereby preventing loss of components, and through matching of particles with different size, sub-micrometer powder is uniformly dispersed in micrometer powder, thereby overcoming low grouting efficiency and nonuniform components. The density of a blank obtained from matching of particles with different size is obviously increased, so that the contraction is reduced and the blank is beneficial for preventing sintering deformation and cracking of a solid-phase sintered silicon carbide ceramic profiled part. Boric acid or / and diboron trioxide is adopted as a sintering aid and is dissolved in a thick liquid, so that the sintering aid is uniformly dispersed, and the density distribution of high-temperature-sintered silicon carbide ceramic profiled part is uniform.

Description

technical field [0001] The invention relates to a preparation method of silicon carbide ceramics, more specifically relates to the preparation of high-performance normal-pressure solid-phase sintered silicon carbide ceramic special-shaped parts by a high-pressure grouting molding process. The invention belongs to the technical field of preparation of engineering ceramic materials. Background technique [0002] Atmospheric pressure sintered silicon carbide ceramics is a kind of good structural ceramics, which has the characteristics of high hardness, high thermal shock performance, high thermal conductivity, good wear resistance and chemical corrosion resistance, and can be applied to almost all corrosion-resistant, resistant Abrasive working conditions, it is an ideal material for special-shaped parts such as container linings and conveying pipes for high-abrasion and high-corrosion fluid substances. [0003] According to different formula systems, silicon carbide ceramics ...

AI Technical Summary

Problems solved by technology

This method has a large amount of grinding, high cost of raw materials and labor, and the parts produced are also relatively limited.

Therefore, we can only use the wet forming method to form special-shaped parts, but the normal pressure sintered silicon carbide ceramics generally use submicron powder or nano powder, the particles are small, and the relative area is large. During the grouting molding process, the gypsum absorbs the capillary force of silicon carbide Insufficient and easy to block the gypsum mold channel, which will affect the grouting process, so that the density of the green body formed cannot meet the requirements of sintering densification, and the mechanical properties such as strength and toughness of the product will deteriorate

Injection molding workpieces contain too much temporary additives and have many pore defects, which are not suitable for the production of high-performance silicon carbide ceramic special-shaped parts; although gel injection molding can prepare complex shapes of normal-pressure sintered silicon carbide ceramic special-shaped parts, a large amount of expensive chemicals are added to the system. Reagent, high cost restricts its large-scale application