(上海交通大学高温材料及高温测试实验室，上海 200030
宝山钢铁公司钢铁研究所，上海 201900)
摘 要: 用EET计算了L12结构Al67Mn8Ti25合金的键结构，键能和主要解理面的解理能。结果表明几种低指数晶面的解理能以{110}晶面为最低，其值为3.12J·m-2；其次为{100}和{111}型晶面，解理能分别为4.17和4.87 J·m-2。用电子背散射衍射技术对合金室温弯曲断口解理刻面的晶体学位向进行了测定，在所测刻面中，{110}刻面约占54%, {100}和{111}约占31%和8%，其结果与EET计算结果相一致。可以认为，解理能低是Al67Mn8Ti25合金室温脆性解理的主要原因之一。
关键字: 金属间化合物 L12结构Al3Ti 价电子结构 解理能 电子背散射衍射
（The State Open Research Lab for High Temperature Materials and Tests,
Shanghai Jiaotong University, Shanghai 200030, P. R. China
Iron and Steel Research Institute, Baoshan Iron and steel Company, Shanghai 201900, P. R. China）
Abstract:The bond structure, bond energy and the cleavage energies of several low-index planes in L12-structured Al67Mn8Ti25 intermetallic compound were investigated by Empirical Electron Theory (EET) of solids and molecules. The results indicated that the plane with the lowest cleavage energy (3.12 J/m2) is {110}. The values of 4.17 and 4.87 J/m2 were obtained for the {100} and {111} planes respectively. The cleavage facets on three-point bonding fractured specimens were determined crystallographically in an electron probe with the electron backscatter diffraction. Among them, the {110} type contains approximately 54%, {100} type about 31% and {111} type about 8%. The results are in good agreement with the EET calculations. This investigation suggests that the low cleavage energy is one of the main reasons for brittle fracture of Al67Mn8Ti25 alloy at room temperature.
Key words: intermetallics; L12-structured Al33Ti ; valence electron structure; cleavage energy; electron backscatter diffraction
