MgO和烧结温度对Al2O3透明陶瓷显微结构和性能的影响

摘要

Al2O3 transparent ceramics were sintered by using high purity Al2O3 powder in H2 atmosphere. The effect of additives and sintering temperatures on densification process, microstructures and properties were investiga ted. Controlled grain growth , increased density and improved sintering performance are related to appropriate doping MgO. The optimum MgO content is.0. 05wt％. With increasing sintering temperature, grains fully develops and light transmittance increases. The optimum sintering temperature is 1850℃. The transparent alumina under the optimum conditions has the average grain size of 20μm at relative density of 99. 62％, the total transmission of 93％, the Vickers hardness of 20. 75GPa and the three-point bending strength of 320MPa.%采用高纯Al2O3粉末为原料,在氢气气氛中烧结了氧化铝透明陶瓷.研究了添加剂MgO和烧结温度对Al2O3透明陶瓷致密化过程、显微结构和性能的影响.实验结果表明,适量掺杂MgO能够抑制晶粒生长,改善烧结性能,提高致密度,0.05%(质量分数)是MgO最佳含量;随着烧结温度的升高,晶粒发育完全,透光率增加,1850℃为最佳烧结温度;在最佳条件下获得的氧化铝透明陶瓷,相对密度为99.72%,平均晶粒尺寸约20μm,总透光率达到93%,显微硬度(HV5)为20.75GPa,抗弯强度达到320MPa.