Al_2O_3陶瓷非等温烧结研究

Study on Al_2O_3 Ceramics Prepared by Non-isothermal Sintering

以高纯α-Al2O3粉体为原料,采用非等温烧结法制备了纯Al2O3陶瓷(AL)及掺杂MgO-Y2O3复合助剂的Al2O3陶瓷(ALMY)。研究了AL和ALMY在不同烧结温度下的相对密度、显微结构及硬度。结果表明,在非等温烧结中,纯Al2O3致密化的烧结温度范围较窄,烧结温度为1500℃时,其相对密度及硬度分别为98.1%和18.1GPa,当烧结温度为1600℃时,AL由于晶粒显著粗化,且产生了晶内气孔,相对密度及硬度分别显著下降到94.6%和12.5 GPa。MgO-Y2O3复合助剂的引入拓宽了Al2O3致密化的烧结温度范围,细化了显微结构,烧结温度在1500℃和1600℃时,ALMY的相对密度均在98%以上,硬度分别为19.2 GPa和17.6 GPa。

Pure Al2O3ceramics（AL） and MgO-Y2O3 binary additives doped Al2O3ceramics（ALMY）were prepared by non-isothermal sintering,using high purity α-Al2O3 powder as the starting materials.The relative density,microstructure and Vickers hardness of the AL and ALMY samples at different sintering temperature were studied. The results show that the sintering temperature range of dense pure Al2O3 ceramics is narrow during non-isothermal sintering. The relative density and Vickers hardness of sample AL sintered at 1500 ℃ is 98. 1% and 18. 1 GPa,respectively. Due to the obvious grain coarsening and the formation of intragranular pores,the relative density and Vickers hardness of sample AL sintered at 1600 ℃ sharply decrease to 94. 6% and 12. 5 GPa,respectively. The introduction of MgOY2O3 binary additives broadens the densification temperature range and refined the grains for Al2O3 ceramics. Vickers hardness of sample ALMY sintered at 1500 ℃ and 1600 ℃ with relative density of over 98% are 19. 2 GPa and 17. 6 GPa,respectively.