Fabrication and plasma arc thermal shock resistance of HfB_2-based ultra high temperature ceramics  

作　　者：翁凌 韩文波 洪长青 

机构地区：[1]School of Material Science and Engineering,Harbin University of Science and Technology [2]Center for Composite Materials and Structures,Harbin Institute of Technology

出　　处：《Journal of Central South University》2012年第4期887-891,共5页中南大学学报（英文版）

基　　金：Project(90505015) supported by the National Natural Science Foundation of China;Project(20060213031) supported by the Research Fund for the Doctoral Program of Higher Education of China

摘　　要：Two hafnium diboride based ceramic matrix composites containing 20% （volume fraction） SiC particle and with or without AIN as sintering additives were fabri,aated by hot-pressed sintering. The mechanical properties and microstructures of these two composites were tested and the thermal shock resistances were evaluated by plasma arc heater. The results indicate that the composite with A1N as sintering additive has a denser and finer microstructure than composite without sintering additive, and the mechanical properties, thermal shock resistance of the composite with A1N as sintering additive are also higher than those of the composite without A1N. Microstructure analysis on the cross-section of two composites after thermal shock tests indicates that a compact oxidation scale contains HfO2 and Al2O3 liquid phase is found on the surface of composite with A1N, which could fill the voids and cracks of surface and improve the thermal shock resistance of composite.Two hafnium diboride based ceramic matrix composites containing 20%(volume fraction) SiC particle and with or without AlN as sintering additives were fabricated by hot-pressed sintering.The mechanical properties and microstructures of these two composites were tested and the thermal shock resistances were evaluated by plasma arc heater.The results indicate that the composite with AlN as sintering additive has a denser and finer microstructure than composite without sintering additive,and the mechanical properties,thermal shock resistance of the composite with AlN as sintering additive are also higher than those of the composite without AlN.Microstructure analysis on the cross-section of two composites after thermal shock tests indicates that a compact oxidation scale contains HfO2 and Al2O3 liquid phase is found on the surface of composite with AlN,which could fill the voids and cracks of surface and improve the thermal shock resistance of composite.

关 键 词：hafnium diboride thermal shock resistance plasma arc test MICROSTRUCTURE 

分 类 号：TQ174.1[化学工程—陶瓷工业]