【摘要】 采用凝胶冷冻干燥法,在-50℃、8Pa的真空度下制备了碱式硝酸钇前驱体.干燥后前驱体呈疏松片状堆积,比烘箱干燥样品具有更为清晰的轮廓.经过1100℃煅烧后,凝胶冷冻干燥处理的粉体具有较细的颗粒,颗粒尺寸分布均一,并且具有较大的比表面积.该粉体经过干压成型,于1700℃真空保温4h烧结后得到晶粒大小均匀的致密多晶透明陶瓷,平均晶粒尺寸在40μm左右,样品相对密度达99.6%.样品经抛光后可见光400nm波长透过率达60%,并且在紫外波段也具有类似于氧化钇单晶的高透过率.更多还原

【Abstract】 The effect of gel-freezing dry method(-50℃,8Pa)was investigated on drying and dewa- tering on a yttrium hydroxynitrate precursor.Precursor through gel-freezing dry accumulated softly with a clearer card-like figure than that through traditional oven dry.After calcination at 1100℃,the powder through gel-freezing dry method has finer particles,narrower particle distribution and larger surface area than that through oven dry.After dry process,samples were sintered at 1700℃for 4h in vacuum,transparent polycrystalline ceramics were produced with uniform crystallines.The mean size of crystallines is around 40μm.Relative density of the transparent ceramic reaches 99.6%.After milling and polishing,samples get a high in-line transmittance of 60% at 400nm wavelength,and it also gets a high in-line transmittance ultraviolet wave band,which is similar to single crystalline yttrium oxide.更多还原