烧结温度对氮化硅陶瓷球显微结构和力学性能的影响

Effect of Sintering Temperature on Microstructure and Mechanical Properties of Silicon Nitride Ceramic Balls

以α-Si 3N 4粉为原料,纳米级Y 2O3和Al 2O3为烧结助剂,采用气压烧结工艺制备氮化硅陶瓷球,研究了烧结温度对陶瓷球显微结构及力学性能的影响。结果表明,随着烧结温度的升高,陶瓷球的维氏硬度和压碎强度先提高后降低,断裂韧性不断提高。烧结温度为1780℃的陶瓷球综合力学性能最佳,其相对密度达到了99%,维氏硬度、断裂韧性和压碎强度分别为1530 HV、7 MPa·m 1/2、296 MPa。

Silicon nitride ceramic balls were prepared by gas pressure sintering process withα-Si 3N 4 powder as raw material and nano Y 2O3 and Al 2O3 as sintering aids.The effect of sintering temperature on microstructure and mechanical properties of ceramic balls was investigated.The results show that with the increase of sintering temperature,the Vickers hardness and crush strength of ceramic balls first increase and then decrease,and the fracture toughness increases continuously.The ceramic balls sintered at 1780℃have the optinal comprehensive mechanical properties,the relative density of which is 99%,the Vickers hardness,fracture toughness and crush strength of which is 1530 HV,7 MPa·m 1/2,and 296 MPa,respectively.