ZrB_2-SiC复相陶瓷的制备及其力学性能研究

Research on Preparation and Mechanical Properties of ZrB_2-SiC Composite Ceramics

本文以ZrB_2和SiC粉为原料,采用Si_3N_4球为球磨介质,通过等静压成型及无压烧结制备了ZrB_2-SiC复相陶瓷,并对ZrB_2-SiC复相陶瓷进行了体积密度、力学性能检测和微观结构分析。结果表明:随着ZrB_2球磨时间的增加,ZrB_2颗粒粒径逐渐减小,复相陶瓷的体积密度逐渐增加;随着SiC含量的增加,复相陶瓷体积密度先增加后略有降低。ZrB_2最佳球磨时间为6 h,SiC最佳含量为20 vol%。ZrB_2-SiC 20 vol%复相陶瓷体积密度达到4.98 g/cm^3,抗弯强度达到331 MPa,断裂韧性达到6.8 MPa/m^2。

In this study, with ZrB2 and SiC powders used as raw materials and Si3N4 as milling medium, ZrB2-SiC composites were prepared by isostatic pressing and pressureless sintering. The density, microstructure and mechanical properties of the composites were investigated. Re- suits showed that with the increase of ZrB2 milling time, ZrB2 particles size was decreased and densities of the composites were increased. With the increase of SiC volume content, the density of the composites were first increased and then decreased a little. The best milling time of ZrB2 was 6 hours and the best content of SiC was 20 vol%. The density of ZrB2＋20 vol%SiC composite is up to 4.98 g/cm^3, the flexural strength is 331 MPa, the fracture toughness is 6.8 MPa/m^2.