短碳纤维增强碳化硅基复合材料的制备与力学性能（英文）

Preparation and Mechanical Property of Short Carbon Fiber Reinforced Silicon Carbide Matrix Composites

利用注浆成型结合反应烧结的方法制备了高强度短碳纤维增强碳化硅基复合材料,研究了分散剂(四甲基氢氧化铵)的含量和混料时间对浆料粘度的影响;短碳纤维的体积分数、碳化硅粉的粒径对复合材料微观结构和力学性能的影响。结果表明,添加0.1wt%的四甲基氢氧化铵得到的浆料粘度最低,混料时间控制在6h为佳。添加35vol%短碳纤维的复合材料的弯曲强度达到(412±47) MPa。由5μm粒径碳化硅粉制备的复合材料的力学性能最佳,其弯曲强度可达(387±40) MPa。将5与50μm粒径的碳化硅粉进行2:1混合后得到的复合材料的力学性能优异,弯曲强度可达(357±41) MPa。

In this study, high-strength silicon carbide(SiC) matrix composites reinforced by short carbon fiber(Csf)(SiC/Csf) were fabricated by slip casting and reaction sintering. The effects of the dispersant(tetramethylammonium hydroxide, TMAH) content and mixing time on the viscosity of the slurry were investigated. In addition, the influences of the volume fraction of Csf and particle size of SiC powder on the mechanical property were also studied. It is found that the viscosity of slurry with 0.1 wt% TMAH is the lowest and the mixing time is preferably controlled at 6 h. The composites with 35 vol% Csf shows the highest flexural strength of(412±47) MPa. The composites with 5 μm SiC powder achieves the highest flexural strength of(387±40) MPa. Grain composition demonstrates that the sample prepared by a mixture of 5 and 50 μm SiC powder at a ratio of 2 to 1 shows relatively excellent mechanical properties with the flexural strength up to(357±41) MPa.