LaPO4／Y-ZrO2陶瓷复合材料的力学性能和可加工性研究

Study of Mechanical Properties and Machinability of LaPO_4/Y-ZrO_2 Ceramic Composites

本文利用电子万能试验机、扫描电子显微镜(SEM)等手段对可切削LaPO4/Y-ZrO2陶瓷复合材料的力学性能、可加工性及其机理进行了研究。结果表明:随着LaPO4含量的增加复合陶瓷的力学性能逐渐下降,可加工性逐渐增加。当LaPO4含量达到30%时,复合陶瓷维持较高的力学性能,其弯曲强度和断裂韧性分别为337.98 MPa和7.2 MPa.m1/2,且具有一定可加工性,其钻削速率为0.014 mm.s-1。当LaPO4含量为50%时复合陶瓷可加工性明显提高,但力学性能下降幅度较大。LaPO4晶粒所具有的层片状断裂性能,强弱界面处裂纹的不连续扩展性及微裂纹扩展出现连通是LaPO4/Y-ZrO2复合陶瓷具有良好的可加工性的主要原因。

Mechanical properties, machinabitity and machining mechanism of LAPO4/ Y-ZrO2 ceramic composites were studied by scanning electron microscope （SEM） and electron versatile machine. The results show that the increasing of LaPO4 will lead to the increasing of machinability and the dropping of mechanical properties of the ceramic composites. With addition of 30% LAP04 , mechanical properties of ceramic composites are improved and the sample can be machined; the bending strength, fracture toughness and drilling rate of ceramic composites are 337.98 MPa, 7.2 MPa · m1/2 and 0. 014 mm· s^-1 , respectively. Machinability of 50% LaPO4/Y-ZrO2 ceramic composites increased obviously but mechanical properties decreased drastically. Layer fracture property of LaPO4 ceramics, cracks discontinous propagation and microcracks connectivity resulting from by weak interfaces between LaPO4 and ZrO2, may be responsible for the good machining properties of the LaPO4/Y-ZrO2 ceramic composites.