Al2O3ZrO2 (Y2O3) PREPARED BY COMBUSTION SYNTHESIS UNDER HIGH GRAVITY
By introducing ZrO2 (4Y) powder into the thermit, Al2O3/ZrO2 (4Y) composite ceramics of different composition and microstmctures were prepared through combustion synthesis under high gravity, and the correlations of composition, microstructures and mechanical properties of composite ceramics were investigated. The results of XRD, SEM and EDS showed that Al2O3/33％ZrO2 (4Y) were composed of random-orientated rod-shaped colonies consisting of a triangular dispersion of orderly submicron-nanometer t-ZrO2 fibers, surrounded by inter-colony regions consisting of spherically-shaped micronmeter t-ZrO2 grains; meanwhile, Al2O3/45％ZrO2 (4Y) were comprised of spherically-shaped micron-meter t-ZrO2 grains. Similar to the international directionally solidified Al2O3/ZrO2 (Y2O3), the EDS results also indicated that there are no impurities, amorphous phases and grain boundaries but clean phase interfaces in two ceramic composites. Compared to the international directionally solidified Al2O3/ZrO2 (Y2O3), the increase in hardness and flexural strength of Al2O3/33％ZrO2 (4Y) in the experiment was due to small-size defect and high fracture toughness induced by compressive residual stress effect and transformation toughening mechanisms; meanwhile, high flexural strength of Al2O3/45％ZrO2 (4Y) was considered to be a result of the fine spherically-shaped t-ZrO2 grains separated from the melt under high gravity, and high fracture toughness induced by transformation toughening and micro-crack toughening mechanisms.
Al2O3/ZrO2 (4Y) combustion synthesis high gravity self-growing rapid solidification
LONG ZHANG ZHONGMIN ZHAO YIGANG SONG WEIGUO WANG HONGBO LIU
Mechanical Engineering College, Shijiazhuang, 050003, China
国际会议
第五届先进材料与加工国际会议(Fifth International Conference on Advanced Materials and Processing ICAMP-5)
哈尔滨
英文
1148-1153
2008-09-03（万方平台首次上网日期，不代表论文的发表时间）