碳化硅粒度对反应烧结碳化硅陶瓷显微结构与性能的影响

摘要

In this paper, D50 = 3.5μm, 5μm, 10μm, 14μm, 20μm five silicon carbide powder were used to prepare a similar density of samples. Investigate the particle size of silicon carbide powder influence the microstructure and mechanical properties of reaction bonded silicon carbide ceramic materials. The results show that: the SiC powder particle size affects the free silicon the size and distribution in the reaction bonded silicon carbide, and the content of free silicon increase with particle size increasing; SiC powder size affects the free silicon content and size,thereby affecting the Bending strength and Fracture toughness of the silicon carbide ceramics. When the particle size of silicon carbide powder is 3.5 μm,the Bending strength value is the maximum(457 MPa),and the Fracture toughness is 3.9 MPa·m0.5.%该文采用D50=3.5μm、5μm、10μm、14μm、20μm的五种SiC微粉制备压坯密度相近的反应烧结碳化硅试样，研究了SiC微粉的粒度对反应烧结碳化硅陶瓷材料显微结构及机械性能的影响。结果表明：反应烧结碳化硅中游离硅尺寸大小和分布受SiC微粉粒度影响，且随着SiC粒度的增大，游离硅含量增多且尺寸增；SiC微粉粒度影响游离硅含量和尺寸大小，进而影响反应烧结碳化硅陶瓷的强度，SiC微粉粒度在3.5μm时，三点抗弯强度为457 MPa，断裂韧性为3.9 MPa·m0.5。