无压烧结制备透辉石增韧补强氧化铝基结构陶瓷材料

Fabrication of diopside toughened alumina matrix structural ceramic materials by pressureless sintering process

采用温度梯度无压烧结工艺制备了透辉石增韧补强Al2O3基结构陶瓷材料,探讨了其烧结致密化特性,对无压烧结后材料的硬度、断裂韧度和抗弯强度进行了测试和分析;分析了复合材料力学性能随透辉石含量变化的关系;探讨了复合材料断面断裂方式的变化对其力学性能的影响。与纯Al2O3相比,透辉石/Al2O3复合材料的力学性能得到明显提高,其中AD3[97%Al2O3+3%(体积分数)透辉石]综合力学性能较好,其硬度、抗弯强度和断裂韧度分别为15.57GPa、417MPa和5.2MPa·m1/2。力学性能提高的主要原因是添加相与Al2O3基体之间界面反应的发生以及透辉石对复合材料的晶粒细化效应。

Diopside toughened alumina matrix structural ceramic materials was developed by using the technology of temperature gradient pressureless sintering. The sintering densification characteristics of the composites were studied in this paper. The hardness, fracture toughness and bending strength of the composites were tested. Meanwhile, the relations of volume content of diopside and mechanical properties of alumina matrix structural ceramic materials were analyzed. The effect of fracture mechanism on the mechanical properties of the composites was studied. Results show that, the mechanical properties of diopside/Al2O3 composites are significantly improved compared with pure alumina. AD3 specimen（97 vol. % Al2O3 ＋ 3 vol. % diopside） , with hardness of 15.57 GPa, strength of 417 MPa and toughness of 5.2 MPa · m^1/2 , shows excellent performances. Interface reactions between the additives and alumina matrix and the good grain refining effect of diopside on alumina contribute to the improvement in mechanical properties.