Al_2O_3-ZrO_2-SiC_W陶瓷复合材料的显微结构和力学性能

MICROSTRUCTURE AND MECHANICAL PROPERTIES OF Al_2O_3-ZrO_2-SiO_w CERAMIC COMPOSITE

通过XRD、SEM、TEM及EPMA技术研究了Al_2O_3-25vol％ZrO_3(2mol％Y_3O_3)-25vol％SiCw(AZS)三元陶瓷复合材料的显微组织和力学性能。试验结果表明,该材料具有较好的强度和韧性配合,ZrO_2与SiC晶须同时起增韧作用。此外,SiC晶须以及弥散分布在Al_2O_3基体中的ZrO_2粒子也提高了该材料的断裂强度。室温下测得该材料的压痕断裂韧性为10.8MPam^(1/2),抗弯强度为676MPa。

The microstructure and mechanical properties of Al2O3 -25 vol % ZrO2 (2mol% Y2O3)-25 vol% SiCw(AZS) ceramic composite are investigated by means of XRD, SEM,TEM and EPMA in the paper. The experimental results show that the material possesses a good combination of strength and toughness. This is considered as a result of combining contribution of the transformation and microcrack toughening of ZrO2 particles with the bridging and pull-out effect of SiC whiskers and bending and deflection of whiskers on cracks. The decrease of Young's modulus associated with ZrO2 additives is inhibited effectively by adding SiC whiskers, and the flexural strength and Vicker's hardness of AZS are also increased by SiC whiskers and ZrO2 particles dispersed in Al2O3 matrix. Moreover, the indentation toughness of hot-pressed AZS shows a clear orientation. The fracture toughness and flexural strength of AZS measured at the room temperature are 10.8MPam1/2 and 676 MPa respectively.