原位催化氮化制备β-SiAlON结合SiC材料

Preparation ofβ-SiAlON bonded SiC composites by in-situ catalytic nitridation

以SiC颗粒、Si粉、Al粉和活性α-Al_(2)O_(3)粉为原料,以Fe为催化剂,采用原位催化氮化法制备了β-SiAlON(z=3)结合SiC材料。研究了氮化温度(分别为1350、1400和1450℃)和Fe加入量(分别为Si粉质量的1%、2%和3%)对合成材料的物相组成、显微结构、显气孔率、体积密度和高温抗折强度的影响。结果表明:氮化温度以1400℃为佳,Fe加入量以Si粉质量的1%为佳;加入Si粉质量的1%的Fe、在1400℃保温3 h氮化制备的试样中生成的β-SiAlON晶须直径较为均匀,试样的氮化程度、致密度和高温抗折强度均较大。

β-SiAlON(z=3)bonded SiC composites were prepared by in-situ catalytic nitridation using SiC particles,Si powder,Al powder and activeα-Al_(2)O_(3) powder as starting materials,and Fe as the catalyst.The effects of the nitriding temperature(1350,1400 and 1450℃)and the Fe addition(1%,2%and 3%of the mass of Si powder)on the phase composition,the microstructure,the apparent porosity,the bulk density and the hot modulus of rupture of the composites were studied.The results show that the optimal nitridation temperature is 1400℃and the optimal Fe content is 1 mass%of the mass of Si powder;the sample prepared at 1400℃for 3 h has uniformβ-SiAlON whisker diameter,higher nitriding degree,density and hot modulus of rupture.