反应烧结制备Si_3N_4/SiC复合材料

Si_3N_4/SiC Composites Prepared by Reaction Sintering

以Si粉为烧结助剂,采用反应烧结工艺制备出Si3N4/Si C复合材料。研究了Si粉添加量、烧结温度对Si3N4/Si C复合材料性能的影响,分别采用X射线衍射仪和材料试验机测试其物相组成和力学性能。实验结果表明:添加40%的Si粉,烧结温度为1600℃时,烧结后Si3N4/Si C复合材料的弯曲强度和断裂韧性分别达到348 MPa和4.82 MPa·m1/2,主要是由于致密度的提高、原位生成Si3N4颗粒的增多以及Si3N4颗粒在Si C基体材料中的弥散增韧。

Si3N4/SiC composites were prepared with Si powder as a sintering aid by reaction sintering method. The influence of Si addition and sintering time on the property of Si3N4/SiC composites was researched. X-ray diffractometer and material testing machine were used to test phase composition and mechanical properties, respectively. The results show that flexural strength and fracture toughness of Si3N4/SiC composites could reach 348 MPa and 4.82 MPa · m^1/2 when Si addition and sintering time were 40% and 1600 ℃, respectively. It is due to the improving of density, the increase of Si3N4 particles by in situ formation, and the dispersion toughening of Si3N4 particles in SiC matrix material.