Sialon陶瓷的常压烧结
来源期刊：中南大学学报(自然科学版)2001年第3期
论文作者：王零森 王有才 樊毅 吴芳
文章页码：277 - 280
关键词：Sialon陶瓷;常压烧结;液相烧结
Key words：Sialon ceramic; pressureless sintering; liquid phase sintering
摘 要：在Si3N4, Al2O3,AlN和Y2O3混合料常压烧结过程中,由于过程反应生成SiO,CO,N2等气相物质和由于Si3N4 原料在高温常压下分解压高,从而常压烧结致密化过程始终伴随着一个失重的塑致密化过程.为了解决这一问题,作者研究了填料成分、烧结温度、烧结时间等工艺条件对Sialon陶瓷常压烧结密度的影响,分析了烧结过程的物理化学机制和致密化机制.4种填料分别为Si3N4, Si3N4+SiO2, Si3N4+ Al2O3+AlN和Si3N4+Al2O3+AlN+BN.被烧料典型配方为: Si3N465%~70%, Al2O320%~25%,AlN 10%,另加6%Y2O3.当填料成分为70% Si3N4+24%Al2O3+3%AlN+3%BN时,制得了相对密度达99%,抗弯强度达612.2 MPa的常压烧结Sialon陶瓷.研究结果表明:对于通式为Si6-ZAlZOZN8-Z的Sialon陶瓷,当Z=2时,其最佳烧结温度为1 750℃,烧结时间为40 min;Sialon的烧结过程是1个多因素控制的瞬时液相烧结过程.
Abstract: During the pressureless sintering of Si3N4, Al2O3, AlN and Y2O3 mixed-powder, as SiO, CO and N gas are produced in the process-reaction and since rawpowder Si3N4 has a higher decomposition pressure at the sintering temperture and pressure, there is a sintering weight loss anti-densification process accompanying the sintering densification process. In order to solve this problem the effect of packing powder compositions, sintering temperature and sintering time on the densities of pressureless sintered Sialon ceramics were studied. The physical and chemical mechanisms of sintering process were discussed. Four kinds of packing powder constitution are A(Si3N4), B(Si3N4+SiO2), C(Si3N4+ Al2O3+AlN) and D(Si3N4+Al2O3+AlN+BN) respectively. The typical composition of feeding powder was Si3N465%~70%, Al2O320%~25%, AlN about 10 %, adding Y2O3%. Sialon ceramic, whose packing powder constitution was 70% Si3N4+24%Al2O3+3%AlN+3%BN, with relative density of more than 99% and bending strength of 612.2MPawas prepared. When Z=2 in the molecular formula ofSi6-ZAlZOZN8-Z, the favorite sintering condition was at temperature 1 750℃and sintering time 40 min. The process of the Sialon sintering was transitional liquid phase sintering,which was controlled by several factors.
