全层片组织TiAl基合金的室温断裂及断裂韧性
来源期刊:中国有色金属学报1997年第4期
论文作者:刘文胜 黄伯云 贺跃辉 陈小群 曲选辉 顾松青
文章页码:115 - 118
关键词:TiAl基合金 全层片组织 断裂韧性
Key words:TiAl-based alloy fully-lamellar microstructure fracture toughness
摘 要:采用标准试样,测试了全层片组织Ti-33Al-3Cr-0.5Mo(质量分数,%,下同)合金的室温断裂韧性(一下简称断裂韧性)。在SEM、TEM先原位观察了板块和薄膜状合金试样中裂纹产生及扩展的动态关系。发现试样的断裂韧性因层片板条取向的不同而呈现各向异性,α2相层片板条对裂纹的扩展具有阻碍作用并使裂尖反生钝化。基于以上原因,使得层片板条取向呈现随机性的合金试样具有高的室温断裂韧性。
Abstract: The fracture toughness of the fully lamellar TiAl -based alloy was measured with standard specimens at ambient temperature. The process of initiation and extension of crack were in-situ observed with plate and foil specimens in SEM and TEM. The results revealed that the fracture toughness of specimens shows anisotropism depend on the lamellar orientation, the α2 phase lath may hinder the extension of crack and make the crack-tip blunt. Thus, the materials with random lamellar orientation exhibits highest room-temperature fracture toughness.