MgO和烧结温度对Al_2O_3陶瓷致密化过程的影响  

Effect of MgO Addition and Sintering Temperatures on Densification Process of Al_2O_3 Ceramics

作　　者：程诚[1] 纪箴[1] 贾成厂[1] 王召利[1] 黄小泓 王聪瑜[1] 

机构地区：[1]北京科技大学新材料技术研究院,北京100083

出　　处：《粉末冶金技术》2015年第4期275-280,284,共7页Powder Metallurgy Technology

基　　金：国际合作项目(2014DFR50570)

摘　　要：以高纯α-Al_2O_3粉体为原料,MgO为烧结助剂,采用放电等离子烧结技术(SPS)制备氧化铝陶瓷。研究了MgO添加量和烧结温度对氧化铝陶瓷致密化过程及显微结构的影响,并分析了烧结过程中气孔的扩散与演变。结果表明:添加适量MgO可以降低氧化铝陶瓷的烧结温度,抑制晶粒长大,提高致密度,0.25%(质量分数)是MgO的最佳添加量;随着烧结温度的升高,晶粒逐渐长大,气孔率降低,1 550℃为最佳烧结温度;在此条件下获得的微米晶氧化铝陶瓷,其相对密度达到99.96%,平均晶粒尺寸约为3μm,且晶粒大小均匀,几乎无异常长大现象。The alumina ceramics were fabricated by spark plasma sintering technique （SPS） , using high purity α-Al2O3 powder as starting material and MgO as sintering aid. The effects of MgO content and sintering temperature on densification process and microstructure were investigated, and the evolution and diffusion of pore in sintering were analyzed. The results show that the addition of MgO can decrease the sintering temperature, inhibit the grain growth and increase the density of the alumina ceramics, and the optimum content of MgO of 0.25% is found. With increasing sintering temperature, grain growth, porosity decrease and densificatioo occur. The optimal alumina is obtained by sintering at 1550 ℃ , doped with 0. 25% MgO, which result in a relative density of 99.96% and a more uniform distribution of matrix grains with an average size of 3 μm and almost completely without abnormal grain growth.

关 键 词：Al_2O_3陶瓷 MGO 放电等离子烧结 致密化 气孔 

分 类 号：TQ174.758[化学工程—陶瓷工业]