| Morphology, substructure, crystal structure and surface relief of martensite as well as the influence of aging on the shape memory effect in the Cu-10.45Al-5.48Mn-2.53Zn and Cu-8.66Al-7.51Mn-4.48Zn shape memory alloy were studied in this paper by means of XRD, Optical Microscope, Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM) and Atomic Force Microscope (AFM) analysis, tensile and bend test and so on. At the same time, the crystallographic character of Cu-8.66Al-7.51Mn-4.48Zn alloy was predicted based on the Phenomenological Theory of Martensite Crystallography (PTMC) and Displacement Vector Theory.It is shown that morphology, phase interface structure and crystal structure were different with the change of the tested alloy component. The martensite morphology of the tested alloy in the Cu-10.45Al-5.48Mn-2.53Zn exhibited the lath-shaped. Various martensite variants were arranged simply in parallel. The substructure of martensite in the tested alloy is confirmed to be (127) twin by calculation and the quenched martensite has N2H structure. Morphology of the Cu-8.66Al-7.51Mn-4.48Zn tested alloy showed spearhead and feather-shaped in most part. The arrangement of the various martensite variants was complex while N18R stacking fault was identified in them.The aging results of parent phase showed that the influence toward microstructure and shape memory effect is different by various aging temperature and time. Thinner lath martensite but invariable microstructure was found after parent phase aging at lower temperature so that highly shape memory effect exhibit in tested alloy. The γ2-phase precipitate during β1|-phase aging at average temperature .Then the quenched martensite has N2H structure for leaning Al in basic body and transforms gradually into N18R with the prolonging of aging time. But the content of martensite was almost unchanged during later aging, and it exhibited a higher recovery ratio. In the high temperature aging treatment, parent phase took the eutectoid reaction (β --> α + γ 2), the content of martensite has intensively decreased after quenching. At the same time, the y γ2-phase precipitate leads to the ductile of alloy became very low and the shapememory properties of the tested alloy toboggan. While, the Cu-8.66Al-7.51Mn-4.48Zn alloy has a lower properties of aging-resistance at average temperature in the parent phase.The stress-induced martensite transformation in Cu-8.66Al-7.51Mn-4.48Zn alloy has been studied by means of tensile test. It is shown that interface structure of martensite lied on the tensile strain, and the recovery ratio had related to tensile strain.The martensite surface relief of the Cu-8.66Al-7.51Mn-4.48Zn alloy was observed and analyzed by means of AFM. It is shown that the single variant of the lath martensite exhibited shaped surface relief, and the spearhead martensite showed "N"-shaped or "tent"-shaped surface. Relief height, width and angle of the single variant were larger than the various variant. Since the excellent properties of self-accommodation, various variants were apt to reorient. Thus, single variant was found and it was avail to coming into being shape memory effect.The crystallographic character of Cu-8.66Al-7.51Mn-4.48Zn alloy was calculated by Phenomenological Theory of Martensite Crystallography (PTMC) and Displacement Vector Theory. It is shown that habit plane is (0.8801 0.3740 0.2958), viz. (311). Meanwhile, effective self-accommodation of martensite variants in this alloy was found by 24 kinds of martensite variants calculation and TEM.
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