(上海交通大學(xué)高溫材料及高溫測試實驗室，上海 200030
寶山鋼鐵公司鋼鐵研究所，上海 201900)
摘 要: 用EET計算了L12結(jié)構(gòu)Al67Mn8Ti25合金的鍵結(jié)構(gòu)，鍵能和主要解理面的解理能。結(jié)果表明幾種低指數(shù)晶面的解理能以{110}晶面為最低，其值為3.12J·m-2；其次為{100}和{111}型晶面，解理能分別為4.17和4.87 J·m-2。用電子背散射衍射技術(shù)對合金室溫彎曲斷口解理刻面的晶體學(xué)位向進行了測定，在所測刻面中，{110}刻面約占54%, {100}和{111}約占31%和8%，其結(jié)果與EET計算結(jié)果相一致。可以認為，解理能低是Al67Mn8Ti25合金室溫脆性解理的主要原因之一。
關(guān)鍵字: 金屬間化合物 L12結(jié)構(gòu)Al3Ti 價電子結(jié)構(gòu) 解理能 電子背散射衍射
（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
