加料方式对共沉淀法制备Nd∶YAG透明陶瓷的影响

Feeding ways during preparing Nd∶ YAG ceramics by co-precipitation method

以Nd2O3、Y2O3、NH4Al(SO4)2·12H2O为原料,NH4HCO3为沉淀剂,采用顺序、反序和并流3种不同共沉淀加料方式,在高滴加速率条件下制取了掺钕钇铝石榴石(Nd∶YAG)粉体,比较工艺操作,表征其相组成、显微形貌、粒度分布和烧结后陶瓷的透过率。结果表明,并流共沉淀工艺无需调节pH值,工艺操作最简单;经1 100℃煅烧,反序、并流法制备的粉体均为纯相YAG,顺序制备的粉体含有杂相,其中并流法制备的粉体粒径分布窄,颗粒呈类球形,粉体活性高。采用真空烧结技术于1 715℃下烧结制备了Nd∶YAG陶瓷,顺序、反序和并流样品在1 064 nm处透过率分别为68%,70%和75%。

Yttrium aluminum garnet （YAG）powders were synthesized by co-precipitation with forward-titration,reverse-titration and parallel flow using NH 4 Al（SO 4 ）2 ·12 H 2 O,Y2 O 3 ,Nd2 O 3 as starting materials and NH 4 HCO 3 as precipitant at a high rate of adding the materials.The difference of the processes was discussed and the phase composition,morphology,particle size distribution of the powders were measured.It was found that parallel flow was simple to operate without adjusting pH value.The powders by reverse titration and parallel flow are of pure-phase YAG,while the powders by forward-titration were of major-phase YAG and a trace amount of other phase.The powders by parallel flow are well dispersed with a narrow size distribution,spherical morphology and the highest activity.After YAG ceramics are sintered at 1 715 ℃ in vacuum,the transmit-tance of mirror-polished samples by forward-titration,reverse-titration and parallel flow were 68%,70%, 75%,respectively.