【摘要】 以金属Al粉、Si粉、SiO2 粉及SiC颗粒为原料 ,在常压氮气及 14 5 0℃～ 15 5 0℃的氮化烧结条件下 ,可获得以 β Sialon为结合相的Sialon SiC复相材料。研究结果表明 :凝胶注模坯体经脱脂处理后可形成贯通的微小孔隙 ,提供了氮气进入坯体的通道 ,使氮化反应充分进行。控制氮化温度为 14 5 0℃～ 15 5 0℃及氧分压PO2 为 10 - 1 8.8～ 10 - 1 7.6 MPa,可使金属Al形成AlN及Al2 O3,成为β Sialon物相组成Si3N4 Al2 O3 AlN SiO2 所需的成分。尽管氮化试验的气体中氧分压远大于 10 - 1 7.6 MPa ,使部分AlN氧化为Al2 O3和N2 ,但氧化过程产生的N2 又使坯体该部位孔隙中的氮分压提高、氧分压降低 ,使Al2 O3与AlN达到热力学共存状态。更多还原

【Abstract】 The Sialon-SiC material, which has the powder of Al, Si, SiO 2, and various granularities of SiC as raw material, has been prepared at nomal pressure N 2 ambience and under 1450℃～1550℃. The results show that many small perforation can be formed through degreasing the green body that is prepared by gel casting, which provides the pathway for N 2 coming into body so as nitridation reaction accomplished. The main component of forming β-Sialon, AlN and Al 2O 3 can be produced through controlling the temperature between 1450℃～1550℃and the pressure of O 2 10 -18.8 ～10 -17.6 MPa. While the pressure of O 2 is much higher than 10 -17.6 MPa, the AlN and Al 2O 3 can still coexist, and AlN is oxided. At the same time the N 2 is produced so that pressure of O 2 is reduced to demanded pressure in small interspace.更多还原