71 巻 (2007) 9 号 p. 672-677
The surface relief caused by stress-induced fcc/hcp martensitic transformation in an Fe-30Mn-5Si-1Al shape memory alloy, which exhibited a good shape memory effect and an improved ductility due to a small addition of aluminum to a conventional Fe-30Mn-6Si shape memory alloy, was quantitatively analyzed by atomic force microscopy. The orientation of an austenite grain was determined with surface traces of four {111}f planes, which made it possible to determine the surface tilt angles for all 12 variants of hcp martensite and deformation twins. On the basis of these values, the stress-induced martensite and deformation twin, coexisting in a grain, were identified by investigating the surface tilt angles. The surface relief caused by the stress-induced martensite recovered after heating above the reverse transformation temperature, but that due to the deformation twin remained unaltered.