| The effects of strain on structure and transformation characteristics of Cu-21wt%Zn-6wt%Al polycrystalline alloys have been studied. The alloys were subjected to tensile and cold rolled deformation. In tensile test, elongation was about 5%. The mechanism of strain recovery of parent phase was pseudoelastic effects by strain induced martensite formation, and that of martensite phase was shape memory effects by coalescence and rearrangement of martensite plate variants. The amount of strain recovery was reduced as increase of deformation. Martensite-to-martensite transformations of cold rolled specimens had been studied by X-ray diffraction and transmission electron microscope. In this alloy composition, 18R martensite structure was transformed to 6R structure by deformation. Parent phase, which had DO₃ structure, was transformed to 18R martensite structure, then it was transformed to 6R structure by further deformation. The procedure of phase change was same as low Al composition alloys. The amount of deformation that 6R structure was stable and peaks were detected by X-ray was about 40% of cold rolling |
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