聚丙烯酸铵和柠檬酸铵分散剂对钇铝石榴石陶瓷透光率的影响

使用超声波-微波辅助的醇盐水解沉淀法合成了Y_3Al_5O_(12)(YAG)前驱体,加入烧结助剂及分散剂后真空烧结制备了YAG透明陶瓷,并对添加不同分散剂烧成的YAG透明陶瓷的晶相结构、微观形貌及光学性能进行了表征。结果表明:添加不同分散剂均可获得纯相YAG透明陶瓷;添加聚丙烯酸铵(NH_4PAA),晶粒之间没有明显的晶界,且气孔较大;添加柠檬酸铵(AC),晶粒分散良好,平均晶粒尺寸约为3μm。未添加分散剂时,YAG透明陶瓷在近红外波段处透光率为76%;添加NH_4PAA时,透明陶瓷透光率较低,仅为51%;而添加AC后透明陶瓷透光率可达到78%。添加AC能够细化YAG透明陶瓷晶粒,促进残余气孔排出,从而使YAG透明陶瓷获得更高的透光率。

Influence of Ammonium Polyacrylic Acid and Ammonium Citrate Dispersants on Transmittance of Yttrium Aluminum Garnet Ceramics

Yttrium aluminum garnet(Y3Al5O12,YAG)transparent ceramics were prepared by vacuum sintering with the ad-dition of sintering aids and dispersants into YAG precursor.The precursor of YAG was prepared via ultrasound-microwave-assisted alkoxide hydrolysis precipitation method.The crystal structures,morphology and optical properties of transparent YAG ceramics with the addition of different dispersant were investigated.The results showed that pure-phase transparent YAG ceramics could be obtained with the addition of all kinds of dispersants.By adding the ammonium polyacrylic acid (NH4PAA),no obvious boundaries were formed between crystalline grains and large pores emerged.With the addition of ammonium citrate (AC),well-dispersed crys-talline grains could be formed with the average size of about 3 μm.The transmittance in the near-infrared waveband of the transparent YAG ceramic was 76% without the addition of dispersants.However,with the addition of NH4PAA,the transmittance of the trans-parent YAG ceramics was reduced to only 51%,and when adding AC it rose back to 78%.The result indicates that AC can refine the grain size of the transparent YAG ceramics and promote the removal of residual pores,thus contribute to the formation of transpa-rent YAG ceramics with higher transmittance.