湿化学法合成YAG纳米粉体及透明陶瓷

Nanocrystalline YAG powders and translucent ceramics by wet-chemical method

分别以AlCl3和YCl3的混合溶液为母盐,碳酸氢铵(AHC)或氨水(AW)为沉淀剂,采用共沉淀法制备了YAG超微粉。AHC法得到的沉淀物经900℃煅烧2h后,全部转变为YAG相,没有YAM和YAP等中间相生成。1100℃煅烧2h后获得的YAG粉体分散性好,一次颗粒尺寸为80nm,具有良好的烧结活性,使用0.5%(质量分数)的正硅酸乙酯(TEOS)作为烧结添加剂,经过1700℃真空烧结5h后,获得了YAG半透明陶瓷。AW法煅烧过程中出现了YAP相,得到的粉体团聚严重,烧结体密度很低。

By using the mixture of aluminum and yttrium chloride and ammonium hydrogen carbonate （AHC） or ammonia water （AW） as the reagent and precipitants, respectively, the nanocrystalline yttrium aluminum garnet （YAG） powder was synthesized by the co-precipitation method. The precursor obtained through the AHC method completely was transformed to YAG phase after calcining at 900℃ for 2 h, and no intermediate YAM or YAP phase was detected during calcining. YAG powders obtained by calcining the carbonate precursor at 1100℃ are well dispersed, the primary particle diameter is about 80 nm and the YAG powders have high sinterability. Translucent YAG ceramics were fabricated after vacuum sintering at 1700℃ for 5 h using 0.5% tetraethyl orthosilicate（TEOS） as sintering aid addition. YAP phase is formed during calcing the hydroxide precursor by AW method. The resultant YAG powders are severely agglomerated and caused low density of the sintered body.