Change in preferential orientation of a phase transforming from b' Cu-Zn alloys with zinc concentration
Ikeno Susumu; Kume Osamu; Yoshimoto Hitoshi; Anada Hiroshi; Matsuda Kenji; Uetani Yasuhiro
Abstract:In order to clarify the effect of Zn concentration on the habit planes of a phase in the b' matrix, an embossing method and SEM- ECP observation were applied to Cu-39.6 mass%Zn alloy and Cu-43.2 mass%Zn alloy. In the both alloys, a phase, which always exists as a pair of plates, had a straight line at the center of the triangular a phase as one of the feature. For the relatively lower Zn content alloy (Cu-39.6 mass%Zn alloy), the habit plane of a phase in b' matrix was found near {3 17 18}m plane of the matrix. In this case, four kinds of crystallographically equivalent habit planes, (3 17 18), (3 18 17), (3 over bar 17 18) and (3 over bar 18 17) existed, and the values of these habit planes were almost equal to those of {5 27 29}m obtained for Cu-41.7 mass%Zn alloy. For the relatively higher Zn content alloy (Cu-43.2 mass%Zn alloy), the habit plane of a phase in b' matrix existed near {3 14 14}m plane of the matrix. Merely two kinds of crystallographically equivalent habit planes, (3 14 14) and (3 over bar 14 14) were found in this alloy. Key Words:Cu-Zn alloy, phase decomposition, beta prime phase, alpha plate, annealing, Habit plane, SEM