焙烧温度对微晶陶瓷磨料晶粒度的影响

Influence of Calcination Temperature on Grain Size of Microcrystalline Alumina Abrasive

在溶胶—凝胶工艺制备微晶陶瓷磨料前驱体技术的基础上,对经烘干、破碎、筛选出的前驱体凝胶颗粒料以两段式烧结法—中温管式炉预烧和高温箱式炉焙烧相结合制备微晶陶瓷磨料。借助TG-DSC、XRD、SEM等技术手段,探讨焙烧温度与制备的微晶陶瓷磨料晶粒度的关系。结果表明:在实验室条件下,以特种氧化铝粉为主要原料采用溶胶-凝胶工艺制备前驱体,以两段式烧结法处理样品,前驱体颗粒料首先以石英舟盛装送入石英管式炉中于800~900℃预烧1 h,然后将预烧料移入莫来石或刚玉—莫来石匣钵中送入马弗炉中于1400~1450℃焙烧30 min,制备试验磨料的原晶晶粒尺寸<1μm,晶粒得到了相应程度的生长,堆积致密、晶间距较小、晶粒度大小相对均匀。

On the basis of sol-gel process for preparing microcrystalline alumina abrasive precursor,the microcrystalline alumina abrasive was prepared after the precursor by heat treating with a two-stage sintering process,firstly precalcining in a medium temperature tube furnace,secondly firing in a high temperature box furnace.The relationship between calcination temperature and grain size of abrasive was explored by means of TG-DSC、XRD、SEM examination and so on.The results show that in laboratory conditions,the precursor particles were prepared through sol-gel process with the main raw material special alumina powder,which by heat-treating at a two-stage sintering process.Precursor particles were burned at 800~900℃for 1 h in quartz boat crucible in a quartz tube furnace,then were fired at 1400~1450℃for 0.5 h in mullite or corundum-mullite sagger in a muffle furnace.The prepared abrasive particles’grain size is smaller than 1μm.The grains grew to a corresponding degree.The primary grain is fabricating compact with smaller crystal spacing and the grain size is relatively uniform.