| The Bauschinger effect was measured by static tension-compression test at room temperature for Cu, Cu-20% Zn, Cu-30% Zn, Cu-40% Zn, and Cu-45% Zn alloys. In this study, Bauschinger stress, strain, energy and back stress were used to explain the Bauschinger effect as parameters. As stacking fault energy (SFE) is lower, slip mainly tend to change from cross slip to planer slip in fcc. In pure Cu and single phase alloys (∼30% Zn) SFE is decreased with increasing of Zn content and the Bauschinger effect strongly relied on slip mode by SFE. Because Bauschinger stress parameter is increased with prestrain, the most important factor affecting the magnitude of the Bauschinger effect seems to be back stress. In (α＋β) two phase alloys (40% Zn and 45% Zn), when prestrain is small, the Bauschinger effect relied on not only macroscopic residual stresses developed as a result of inhomogeneous deformation of the (α＋β) phases but also back stress. But if prestrain is raised, the Bauschinger effect relied on back stress only. To evaluate the Bauschinger effect precisely, we should use more than two parameters, because Bauschinger parameters showed the different results each other. |
|
