BN-O’-SiAlON复合材料抗热震性能研究  

Thermal shock resistance of BN-O'-SiAlON composites

作　　者：甄强[1] 高林[1] 倪亮[1] 孙桂春[1] 张中伟[2] 

机构地区：[1]上海大学材料科学与工程学院纳米科学与技术研究中心,上海200444 [2]先进功能复合材料技术国防科技重点实验室,北京100076

出　　处：《耐火材料》2010年第4期272-275,279,共5页Refractories

基　　金：中国人民解放军总装备部武器装备预研基金项目(9140C5601010701;9140C5601010801);上海市教育委员会重点学科建设项目资助(J50102);教育部重点项目(208043);上海市教委重点项目(07ZZ10);上海市科委人才计划(09QT1400300)

摘　　要：采用热压烧结合成了BN-O’-SiAlON复合材料,通过XRD、SEM、TEM对材料的显微结构进行了表征,并采用水冷法研究其在不同热震温差(400～1 500℃)下的抗热震性能。研究表明,柱状的O’-SiAlON晶粒的弥散强化和桥联作用等增韧机制,材料内部存在的亚临界自发微裂纹,以及无规则取向的BN和O’-SiAlON晶粒相互交叉生长构成的网状结构,均有利于改善BN-O’-SiAlON复合材料的抗热震性能。虽然理论计算近似得出在热震过程中BN-O’-SiAlON复合材料中存在的热性能失配将导致较大的热应力,但实际上,在低于900℃的热震温差下材料的强度并没有明显降低,而在高于900℃的热震温差下才有较明显下降,直到达到1 500℃的热震温差时,其强度仍然保持在原来的40%左右,这说明BN-O’-SiAlON复合材料具有良好的抗热震性能。The BN-O＇-SiAlON composites were synthesized by hot-pressing sintering.Microstructures were characterized by XRD,SEM,and TEM.The thermal shock resistance at different thermal shock temperature differences（400-1 500 ℃） was studied by water quenching method.The results show that the dispersion strengthening and bridging toughening of columnar O＇-SiAlON grains,the sub-critical spontaneous microcracks within materials,and cross-growth network structure of irregular orientation of BN and O＇-SiAlON＇s grains can improve the thermal shock resistance of BN-O＇-SiAlON composites.The theoretical calculation shows that the thermal mismatch of BN-O＇-SiAlON composites will lead to great thermal stress in thermal shock process.However,when thermal shock temperature difference is lower than 900 ℃,the strength of the material doesn＇t significantly reduce;when higher than 900 ℃,the strength starts to reduce;even when reaches 1 500 ℃,the strength still remains at about 40% of the original,which shows the BN-O＇-SiAlON composites have good thermal shock resistance.

关 键 词：BN-O-’SiAlON 显微结构 抗热震性 热震温差 

分 类 号：TQ174.758[化学工程—陶瓷工业]