碳化硅晶须补强氧化铝复合材料的制备及其力学性能  

Preparation and Mechanical Properties of SiC Whisker-Reinforced Alumina

作　　者：彭晓峰[1] 黄校先[1] 张玉峰[1] 

机构地区：[1]中国科学院上海硅酸盐研究所,上海200050

出　　处：《无机材料学报》1998年第4期469-476,共8页Journal of Inorganic Materials

基　　金：上海市发展基金资助

摘　　要：本论文利用商用γ-Al2O3粉体和上海硅酸盐所制备的碳化硅晶须，通过热压工艺来制备碳化硅晶须补强氧化铝复合材料．当晶须含量为30vol％时，室温下复合材料的抗弯强度为812±38MPa，断裂韧性为8．8±0．1MPa·m1／2；在1200℃、Ar气氛下，分别为560±61MPa和6．1±0．4MPam1／2．在氮气氛下，由于晶须的损伤易导致材料的力学性能下降．添加剂可降低复合材料的烧结温度，但不利于其力学性能．显微结构观察发现，不同温度下，AS复合材料的增韧机理有变化．SiC whisker reinforced alumina composites were fabricated by hot-pressing from the commercial γ-Al2O3 and SiC whisker made in Shanghai institute of Ceramics. We obtained some samples with 30vol% SiCw hot-pressed at 1800℃ in Ar atmosphere having the flexure strength of 812±38MPa and fracture toughness of 8.8±0.1MPa·m1/2 at room temperature; 560±61MPa and 6.1±0.4MPa at 1200℃ respectively. The small amount of additions accelerated densification but reduced the mechanical properties. In N2 atmosphere, SiC whisker would be injured and the composites mechanical properties degraded. Moreover, the microstructural observations indicated that the toughening mechanism of AS composites is different from whiskers pull-out and matrix's cleavage fracture at room temperature to whiskers/matrix interface debonding and matrix's intergranual fracture at high temperature.

关 键 词：晶须补强 力学性能 碳化硅 氧化铝 复合陶瓷 

分 类 号：TQ174.758[化学工程—陶瓷工业]