定向凝固NiAl-15Cr合金的高温拉伸性能和韧脆转变条件  

High Temperature Tensile Properties and Brittle-to-Ductile Transition of Directionally Solidified NiAl-15Cr Alloy

作　　者：肖思文[1] 

机构地区：[1]湖南科技大学机电工程学院,湘潭411201

出　　处：《机械工程材料》2010年第5期60-63,共4页Materials For Mechanical Engineering

摘　　要：研究了定向凝固NiAl-15Cr合金的显微组织、高温拉伸性能和韧脆转变条件。结果表明:该合金显微组织为枝晶状,枝晶干为β-NiAl相、枝晶间为γ相和过渡层为γ′相;合金具有很好的高温塑性和高温强度,并在1 323 K时表现出类超塑性行为;同时它具有明显的韧脆转变温度,当应变速率为1.11×10^(-4)s^(-1)时,韧脆转变温度为873 K,应变速率提高两个数量级后,韧脆转变温度升高约150 K。The microstructure,high temperature tensile properties and brittle-to-ductile transition condition of directionally solidified NiAl-15Cr alloy had been investigated.The results show that the microstructure was dendritic shape.The dendrite arm wasβ-NiAl phase,γphase was in interdendritic region and transient layer wasγ＇ phase.The alloy showed good plasticity and strength at high temperatures and superplasticity-like deformation behavior at 1 323 K.And it had obvious brittle-to-ductile transition temperature（BDTT）,which was 873 K as the strain rate was 1.11×10^（-4） s^（-1）.When the initial strain rate increased by two order of magnitude,the BDTT increased by approximate 150 K.

关 键 词：定向凝固 NIAL 金属间化合物 韧脆转变 

分 类 号：TG146[一般工业技术—材料科学与工程]