材料期刊网

以片状氧化铝晶种作为第二相,采用无压烧结制备了氧化铝陶瓷,分析了片状氧化铝含量对氧化铝陶瓷微观结构的影响,采用扫描电子显微镜（SEM）观察分析试样的断口形貌;采用压痕法计算试样的断裂韧性（KIC）值;研究了不同含量的晶种引入量对氧化铝陶瓷断裂韧性的影响。结果表明烧结温度为1575℃时,相对致密度可以达到96.7%;片状氧化铝晶种的引入能够显著提高氧化铝陶瓷的断裂韧性;其片晶的裂纹偏转、片晶拔出效应等增韧机制发挥了主导作用;随着片状氧化铝含量的提高,氧化铝陶瓷的力学性能逐渐提高,当掺杂含量达到35%（质量分数）时,KIC达到6.4MPa.m1/2,当含量继续增加,KIC呈现逐渐降低的趋势。

The effects of plate-like alumina seed amount on the microstructure and properties of alumina ceramics prepared by pressureless sintering were studied,when plate-like alumina seed was used as the second phase.The effects of plate-like alumina content on the microstructure of fracture surface of alumina ceramics were studied by SEM.The fracture toughness（KIC） of specimen was calculated by the indentation method and the effects of crystal seed with different contents on the fracture toughness of alumina ceramic were studied.The results demonstrate that the relative density of alumina ceramics reaches 96.7% when sintering temperature is 1575℃.The fracture toughness of alumina ceramics increases gradually as crack deflection and plate-like alumina seed pullout working.With the content of the plate-like alumina increasing,the mechanical properties of alumina ceramic gradually increased.When 35wt % seeds were added,the fracture toughness can reach 6.4MPa·m1/2