镁铝合金添加剂对SiC-MgAl_(2)O_(4)材料显微结构和性能的影响  

Effect of Mg-Al Additive on Microstructure and Properties of SiC-MgAl_(2)O_(4)Materials

作　　者：王梦强 陈留刚 孙红刚[2] 杜一昊 司瑶晨 李红霞 WANG Mengqiang;CHEN Liugang;SUN Honggang;DU Yihao;SI Yaochen;LI Hongxia(Henan Key Laboratory of High Temperature Functional Ceramics,School of Materials Science and Engineering,Zhengzhou University,Zhengzhou 450001,China;State Key Laboratory of Advanced Refractories,Sinosteel Luoyang Institute of Refractories Research Co.,Ltd.,Luoyang 471039,Henan,China;School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]郑州大学材料科学与工程学院,河南省高温功能材料重点实验室,郑州450001 [2]中钢集团洛阳耐火材料研究院有限公司先进耐火材料国家重点实验室,河南洛阳471039 [3]北京科技大学材料科学与工程学院,北京100083

出　　处：《材料导报》2024年第16期75-80,共6页Materials Reports

基　　金：国家自然科学基金(U21A2059)。

摘　　要：为探索煤气化用耐火材料的无铬化,本研究采用碳化硅颗粒和镁铝尖晶石细粉为主要原料制备SiC-MgAl_(2)O_(4)复合耐火材料,于流动氮气中500~1450℃热处理,对比未添加和添加4%(质量分数)镁铝合金粉的复合材料在热处理升温过程中的微观结构及性能变化,探究镁铝合金氮化烧成中形成的低维相对SiC-MgAl_(2)O_(4)复合材料性能的改善效果。结果表明,镁铝合金与热处理环境中的N 2、O_(2)的反应温度区间为650~800℃,主要反应产物为AlN和MgO。添加镁铝合金后的试样在700℃形成蜂窝状MgAl_(2)O_(4)尖晶石,增强了SiC骨料和MgAl_(2)O_(4)基质间的结合,此时试样的常温力学强度达到最高;900~1300℃时,MgAl_(2)O_(4)尖晶石由蜂窝状转变为棒状,1300~1500℃时,其再转变为片状、粒状的MgAlON尖晶石,这些形貌和物相的转变伴随体积膨胀,导致试样的强度小幅下降。镁铝合金的添加能使SiC-MgAl_(2)O_(4)在较低温度热处理下原位形成尖晶石,从而提高材料的力学性能。In order to explore the chromium-free refractories for coal gasification,SiC-MgAl_(2)O_(4)materials were prepared using SiC particles and MgAl_(2)O_(4)powder.Microstructure and properties of the composites with or without 4wt%Mg-Al alloy after heat-treating at temperature range of 500—1450℃under N_(2)gas flow were investigated.Explore the formation of low-dimensional phase in nitriding sintering of Mg-Al alloy to improve the performance of SiC-MgAl_(2)O_(4)composite materials.The results show that the Mg-Al alloy reacted with N_(2)and O_(2)at 650—800℃,predominantly forming AlN and MgO.Honeycomb-like MgAl_(2)O_(4)spinel was formed at 700℃enhancing the bonding level between SiC aggregate and MgAl_(2)O_(4)matrix and thus increasing the mechanical strength of the composites.The honeycomb-like MgAl_(2)O_(4)spinel changed from honeycomb into rod shape at 900—1300℃,and then into flake and granular MgAlON at 1300—1500℃.The changes in morphology and phase composition are accompanied by volume expansion,resulting in a slight decrease in the strength of the sample.The addition of Mg-Al alloy can improve the mechanical properties of SiC-MgAl_(2)O_(4)by in-situ formation of spinel under low heat treatment.

关 键 词：复合耐火材料 镁铝尖晶石 氮化反应 镁铝合金 

分 类 号：TQ175[化学工程—硅酸盐工业]