氮化反应合成β’-Sialon材料的工艺研究

Research on synthesizing technique of β'-Sialon material by nitridation reaction

研究了以硅粉、铝粉和氧化铝粉为原料氮化反应制备不同Z值 β’ Sialon材料的氮化工艺制度 :以 10℃·min- 1的升温速度升到 6 0 0℃ ,再以小于 2℃·min- 1的升温速度升到 70 0℃ ,保温 2 .5h ;以 10℃·min- 1的升温速度升到 12 0 0℃ ,再以 2℃·min- 1的升温速度升到 135 0℃ ,保温 6h。炉内气氛为流动氮气 ,流速小于 0 .2m3 ·h- 1。所有试样的氮化率都在 80 %以上 ,说明该工艺制度是合适的。物相分析表明 :氮化最终产物以 β’ Sialon为主 ,高Z值试样残余较多的α Al2 O3 ,并伴生少量15R相 ;烧结后试样的 β’ Sialon呈棱柱状。

β'-Sialon materials were synthesized by nitridation reaction with metallic silicon powder,aluminum powder and alumina powder as starting materials.The nitridation technique systems,including (1) from room temperature to 600 ℃ at 10 ℃·min -1,600 ℃ to 700 ℃ (holding for 2.5 h) at lower than 2 ℃·min -1 and (2) from room temperature to 1200 ℃ at 10 ℃·min -1,1200 ℃ to 1350 ℃ (holding for 6 h) at 2 ℃·min -1,with flowing nitrogen as furnace atmosphere and flow rate lower than 0.2 m 3·h -1,for preparing β'-Sialon materials with different Z-values were researched. The results indicate that the nitridation rate of all of the specimens are more than 80%,showing the nitridation technique systems are reasonable.XRD analysis results reveal that β'-Sialon phase primarily exists in the final product after nitridation,a small amount of α-Al 2O 3 and 15R polytypoid phase remains in the specimens with high Z-values.β'-Sialon phase in the sintered specimens shows hexagonalprism-like microstructure.