气化炉渣合成Ca-α-Sialon–SiC复相陶瓷  

Synthesis of Ca-α-Sialon–SiC Multiphase Ceramics Using Gasification Slag

作　　者：尹洪峰[1] 汤云[1] 任耘[1] 张军战[1] 

机构地区：[1]西安建筑科技大学,西部建筑科技国家重点实验室培育基地,西安710055

出　　处：《硅酸盐学报》2011年第2期233-238,共6页Journal of The Chinese Ceramic Society

摘　　要：利用X射线荧光分析仪、X射线衍射仪、扫描电子显微镜等研究了Texaco气化炉炉渣的化学组成、物相组成和显微结构。以气化炉渣为原料,分别在1 350,1 400,1 450℃和1 500℃4种氮化温度下碳热还原氮化,利用物相确定和显微结构分析等研究了氮化温度对反应的影响。以1 450℃氮化产物为原料,热压制备了Ca-α-sialon–SiC复相陶瓷,并对此材料的力学性能进行了检测。结果表明:(1)Texaco气化炉炉渣主要化学成分为SiO2,Al2O3,CaO和残余碳,其中大多为玻璃相和无定形物质;(2)低温氮化产物主晶相为β-sialon和Ca-α-sialon,高温氮化产物主晶相为Ca-α-sialon和SiC,提高氮化温度更有利于CaO固溶于sialon形成Ca-α-sialon,在1 450℃碳热还原氮化可合成主要成分为Ca-α-sialon和SiC的复相粉体;(3)随着热压温度的升高,Ca-α-sialon-SiC复相陶瓷致密化程度增加,硬度和断裂韧性均有提高,添加剂对材料的力学性能影响较大,添加3%(质量分数,下同)Y2O3+2%MgO,1 650℃热压制备的复相陶瓷的Vickers硬度可达18 GPa,断裂韧性为5.2 MPa?m1/2。The chemical composition,phase constituents and microstructure of gasification slag from Texaco gasifier,the carbother-mal reduction nitridation of gasification slag under four different nitriding temperatures of 1 350,1 400,1 450 and 1 500 ℃ were investigated by X-ray fluorescence spectrometry,X-ray powder diffractometry and scanning electron microscopy.The effect of nitri-dation temperature on the reaction in process was studied by comparing the chemical composition and morphology of nitridation re-action products.Ca-α-sialon–SiC materials were fabricated by hot-press using the reaction product formed under 1 450 ℃ as main raw materials,their mechanical properties were also characterized.The results show that：（1） The main chemical constituents of gasi-fication slag are SiO2,Al2O3,CaO and residual carbon.Their main phase are vitreous glass and amorphous carbon;minor phase are quartz and calcite.（2） The main phases in product formed at lower temperature are β-sialon and Ca-α-sialon;Ca-α-sialon and SiC are largely formed at higher temperature.Ca-α-sialon–SiC powders are produced by carbothermal reduction nitridation process at 1 450 ℃.（3） With the increase of hot-press temperature,the density of Ca-α-sialon–SiC composite ceramic increases,its hardness and fracture toughness are improved.The additives have a great influence on mechanical properties of material,and the Vickers hardness and fracture toughness of the composite ceramic hot-pressed at 1 650 ℃with the addition of 3%（in mass,the same below） Y2O3＋2% MgO,are 18 GPa and 5.2 MPa？m1/2,respectively.

关 键 词：SIALON 碳化硅 气化炉渣 碳热还原氮化 复相陶瓷 力学性能 

分 类 号：TQ546[化学工程—煤化学工程]