Original paper(Vol.46 No.5 pp.464)
Habit plane of a phase with characteristic shape in Cu 43.2 mass%Zn alloy
Ikeno Susumu; Kume Osamu; Terayama Kiyoshi; Matsuda Kenji; Uetani Yasuhiro
Abstract:A habit plane of plate like a phase with peculiar wavy shape in a Cu-43.2mass%Zn alloy was investigated by the observation of Scanning Electron Microscope (SEM) and measuring of SEM-Electron Channeling Pattern (SEM-ECP).
The results obtained are summarized as follows.
(1) a phase having a wavy shape cross-section was observed at low magnification. It became clear that the a phase has a `galvanized sheets' shape, with the use of observation technique of relief images of a phase by preferential etching of matrix.
(2) The preferential growth direction of the a phase is parallel to < 556 > matrix direction and the mean deviation angle between a plane of a phase and {011} band of SEM-ECP at {001} matrix plane was about 7 degrees. A habit plane obtained from the both relations is nearly {155}.
(3) When the a phase grows in the cross sectional direction, the shape becomes round and it looked like a bar with smooth outline at low magnification. From the apparent feature of a phase, which differs from the real, the preferential growth direction and the habit plane of the bar nearly equal to < 111 > matrix direction and {112} matrix plane, respectively.
Key Words:Cu-Zn alloy, phase decomposition, b' phase, annealing, habit plane, SEM-ECP