煅烧工艺对溶胶凝胶制备微球形氧化铝的影响

摘要

By using industrial pseudo-boehmite prepared spherical alumina powder with sol-gel and spray granu-lation technology,the powder was calcined at different temperatures in the muffle furnace.SEM was used to observe the microstructure of the powder obtained.The phase composition of the powder calcined at different temperatures was probed with XRD.The size distribution of powder was tested by using mastersize.And integrated surface rough-ness tester was used to test the surface roughness of the workpiece.The results show that the shape of the powder prepared through spray granulation and calcination is spherical.In addition,as the temperature increases gradually, the phase changes fromγ-Al2 O3 intoθ-Al2 O3 ,and then intoα-Al2 O3 .When the calcination temperature is too high, the power will bond with each other.If the time of heat preservation is prolonged,the powder will grow along the dense area.And when the powder has good crystallinity and more uniform size,its polishing performance is much bet-ter.%以工业级拟薄水铝石为原料,采用溶胶凝胶及喷雾造粒技术制备球形氧化铝粉料,将粉料置于马弗炉中,分别在不同温度下煅烧,采用 SEM观察获得粉体的微观形貌, XRD分析了不同煅烧温度粉体的相组成,马尔文激光粒度仪测定粉体的粒度组成,集成表面粗糙度仪测定被抛光工件的表面粗糙度。结果表明：经喷雾造粒和煅烧后制得的粉料外形为球体；煅烧温度逐步提高时,其物相的变化规律由γ-Al2 O3转变为θ-Al2 O3,再转变为α-Al2 O3相；煅烧温度过高时,将造成粉料颗粒间相互粘结,适当延长保温时间会促使粒子沿着致密区长大。并且,结晶度较好、粒度分布均匀的粉料抛光性能较好。