超重力下燃烧合成ZrO_2(4Y)/Al_2O_3的成分、显微组织与力学性能  

Composition,microstructures and mechanical properties of ZrO_2(4Y)/Al_2O_3 prepared by combustion synthesis under high gravity

作　　者：宋亚林[1] 赵忠民[1] 张龙[1] 杨权[1] 曲振声[1] 

机构地区：[1]军械工程学院先进材料研究所,石家庄050003

出　　处：《复合材料学报》2009年第3期138-146,共9页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金(50672131)

摘　　要：采用超重力下燃烧合成技术,通过调整ZrO2体积分数,制备出不同成分与显微组织形态的ZrO2(4Y)/Al2O3复合陶瓷,研究了材料成分、显微组织与力学性能之间的关系。XRD、SEM和EDS结果表明:当ZrO2体积分数低于37%,陶瓷熔体生成为生长取向各异且以ZrO2四方相亚微米纤维镶嵌于α-Al2O3上的棒状共晶团为基体的复合陶瓷;当ZrO2体积分数高于40%,复合陶瓷基体则生长为略呈球形的ZrO2四方相微米晶粒。性能测试结果显示,随着ZrO2体积分数增加,陶瓷相对密度逐渐降低,陶瓷硬度与断裂韧性均在ZrO2体积分数为33%时出现最高值,而陶瓷弯曲强度则在ZrO2体积分数为29%达到最大值。By using the combustion synthesis under high gravity and adjusting the volume fraction of ZrO2, ZrO2 （4Y）/Al2O3 composite ceramics with different compositions and micro- structural morphologies were prepared, and the correlations of the composition, microstructures and mechanical properties of the materials were investigated. The results of XRD, SEM and EDS show that as the volume fraction of ZrO2 is below 37%, the ceramic matrix grows from the melts to be the random-orientated rod-shaped colonies, of which the submicron-meter fibers of tetragonal ZrO2 are orderly embedded in the α- Al2O3. As the volume fraction of ZrO2 is above 40 %, the ceramic matrix develops to be the tetragonal ZrO2 grains which are shaped like spheres. The results of mechanical properties indicate that the relative density of the ceramics decreases with increasing the volume fraction of ZrO2 , the hardness and fracture toughness of the ceramics simultaneously have the maximum values as the volume fraction of ZrO2 is 33%, and the bending strength of the materials has the maximum value as the volume fraction of ZrO2 is 29 %.

关 键 词：ZrO2(4Y)/Al2O3 燃烧合成 超重力 晶体生长 

分 类 号：TB332[一般工业技术—材料科学与工程]