配料Z值对常压烧结Sialon结构与性能的影响

来源期刊：中南大学学报(自然科学版)2001年第2期

论文作者：王零森 王有才 樊毅 吴芳

文章页码：173 - 175

关键词：Sialon;常压烧结;晶格常数

Key words：Sialon; pressureless sintering; lattice parameter

摘    要：由于Si_6-ZAl_ZO_ZN_8-Z(Z值变化范围为0~4.2)制备过程中物理、化学反应十分复杂,同时几乎没有可能制备单晶全致密Sialon材料,从而使Z值的精确控制十分困难.然而,大量研究表明,Z值对材料的结构和性能,如晶格常数、密度、硬度、断裂韧性、强度等有重要的影响.用Si₃N₄, Al₂O₃,AlN,Y₂O₃混合料以聚乙烯醇(PVA)为成型剂,用模压法成型,单位压制压力为78.5 MPa,烧结在石墨电阻炉中进行,以Si₃N₄+Al₂O₃+AlN+BN混合粉为烧结填料,工业氮气为保护气氛,制得了相对密度大于99%,抗弯强度为612.2 MPa的Sialon陶瓷.结果表明:在一定实验条件下,Z为1和2的材料烧结致密化程度最好,强度随烧结坯密度增加呈指数增加,要获得高的强度,材料密度不能低于3.2 g/cm³;晶格常数a随Z值增加呈线性增加,c值随Z变化规律不明显;Z值为1~2的材料烧结性能最好.

Abstract: The general stoichiometrical composition of β′-Sialon is Si_6-ZAl_ZO_ZN_8-Z.Z changes from 0 to 4.2. The fabrication of Sialon involves complex physical and chemical reactions, so crystallized full density Sialon matericals can hardly be formated, and the value of Z is difficult to adjust precisely. The value of Z is a fundamental factor which decides the construction and main properties of pressure less sintered Sialon ceramics, such as lattice parameter, density,hardness, toughness, bending strength,et al. A Sialon ceramics with the relative density more than 99% and bending strength up to 612.2 MPa was prepared by pressureless sintering of the powder mixture of Si₃N₄, Al₂O₃,AlN,Y₂O₃. It was discovered that the Sialon prepared by the feeding value of Z=1, 2 had higher densification, and the bending strength increased exponentially with densities increasing. It was also discovered that lattice parameters (a) increased with Z value increasing.