Sialon／SiC复相材料研究进展

Porgress on the Development of Sialon/SiC Nultiphase Materials

根据相图，合成Ｓｉａｌｏｎ相的技术途径包括采用Ｓｉ＿３Ｎ＿４粉末和其它反应添加物以无压或热压工艺高温合成，或以Ｓｉ粉与其它金属及其氧化物为原料无压反应烧成而成。Ｓｉａｌｏｎ粉末也可通过粘土类矿物的碳热还原反应来合成。但前两种技术途径在原料及合成工艺上的高成本使其难于在耐火材料领域大规模开发应用。后一种工艺目前仅见到合成Ｓｉａｌｏｎ粉末的试验报道。本研究在对粘土类矿物合成Ｓｉａｌｏｎ粉末的研究基础上，由廉价原料直接合成Ｓｉａｌｏｎ结合ＳｉＣ制品。该工艺具有简单、成本低、合成温度较低及物相组成较纯等特点，为Ｓｉａｌｏｎ结合ＳｉＣ复相材料在耐火材料领域大规模推广应用提供了新的技术途径。

Technological routes for preparing sialon solid solution include pressureless or hot-press sintering of Si_3N_4powder and other additives or nitriding of silicon,aluminum and its oxides at high temperature in nitrogen atom-sphere,based on phase diagrams. Sialon powder can also be obtained by carbonthermal reduction of clay. But thetwo former methods are not widely used in refractories industry because of the higher expenses of both startingmaterials and manufacturing process. Sialon bounded SiC refractory product with excellent properties is succesful-ly developed by one step manufacturing process with cheaper raw materials, shorter operating circle period andlower sintering temperature which is a new suitable process to be widely used in special refractories.