作　　者： ; ; ; ; ;

机构地区： 湖南科技大学机电工程学院

出　　处： 《材料工程》 2006年第11期30-35,共6页

摘　　要： 研究了定向凝固NiAl-28Cr-5．85Mo-0．15Hf合金的微观组织与在293～1373K温度范围内的力学性能，结果表明：合金是由NiAl枝晶轴和枝晶间区（NiAl和Cr（Mo）相的共晶）组成的。经过长期固溶时效处理NiAl／Cr（Mo）合金析出少量弥散分布的Huesler相，其余Hf以固溶体方式存在。DSNiAl-28Cr-5．85Mo-0．15Hf合金具有明显的韧脆转变行为，韧脆转变温度依赖于应变速率。室温拉伸断口呈现明显的解理断裂，而韧脆转变温度在以上时，合金具有较大的变形量，断口上有许多韧窝，呈现明显的塑性断裂特征。 The microstructure and mechanical properties of NiAl-28Cr-5.5Mo-0.15Hf alloy have been investigated at the temperature range of 293-1373K. The results showed that the heat treatment DS NiAl-28Cr-5.5Mo-0. 15Hf alloy was composed of three phases, which were a lamellar Cr（Mo） phases, NiAl matrix and a semicontinuous distributed Ni2Al Hf phase with little amount. The other Hf element existed via solution. It was also observed that the brittle-to-ductile transition for this multiphase alloy was sensitive to strain rate. At the room temperature, the fracture was characterized by predominantly debonding. Beyond the BDTT, the fracture of tested specimens with larger elongation was characterized by large amount of void at the fracture surface.

关 键 词： 定向凝固 韧脆转变 力学性能

领　　域： [金属学及工艺] [一般工业技术] [金属学及工艺] [金属学及工艺] [金属学及工艺]