Boride reinforced silicon carbide ceramics and preparation method thereof

Abstract

The invention discloses a preparation method of boride reinforced silicon carbide ceramics, taking silicon carbide powder, yttrium aluminum garnet and boride micro-powder as main raw materials and comprising the following steps: 1. adding the main raw materials, binding agent and dispersant into de-ionized water followed by ball-milling and mixing to prepare water-base silicon carbide slurry; 2. spray drying the water-base silicon carbide slurry with a spray granulating technique to obtain the silicon carbide granulation powder; 3. molding the silicon carbide granulation powder by dry pre-pressing and cold isostatic final pressing to obtain high density silicon carbide green brick; and 4. placing the high density silicon carbide green brick in a vacuum pressure-free sintering furnace to be heated to 1,900-2,000 DEG C and kept for 1-1.5 hours to obtain boride reinforced silicon carbide ceramics. The boride reinforced silicon carbide ceramics prepared by the method has the characteristics of high hardness, high bending resistance, and excellent fracture toughness property, etc.

Description

technical field [0001] The invention relates to a boride-enhanced silicon carbide ceramic and a preparation method thereof. Background technique [0002] Silicon carbide ceramics is a high-performance structural material with many excellent properties, such as high mechanical strength, large elastic modulus, high hardness, good wear resistance, high temperature resistance, good thermal shock resistance, strong oxidation resistance, Good thermal stability, high thermal conductivity, good chemical corrosion resistance, etc. Silicon carbide ceramics have been widely used in machinery, electronics, metallurgy, petrochemical and other fields and national defense industry, and have been recognized internationally as the fourth basic material since metal, alumina, and cemented carbide. Although silicon carbide ceramics have many properties, their low room temperature strength, insufficient toughness, and difficulty in molding also limit its application. With the development of sc...

AI Technical Summary

Problems solved by technology

At present, there have been reports on boride-silicon carbide composite ceramics, but the main phases are all borides, such as ZrB 2 - SiC, HfB 2 -SiC, the proportion of silicon carbide is only between 5% and 25%

Moreover, these composite ceramics are usually sintered by hot pressing or hot isostatic pressing, and the sintering temperature is high, generally above 2000°C. The process is complicated and the cost is high, which is not conducive to industrial production.