2007 年 48 巻 4 号 p. 869-877
High-resolution transmission electron microscopy revealed that the NbC carbides precipitating in Fe-Mn-Si-based shape memory alloys in the orientational relationship of [100]f||[100]NbC, (001)f||(001)NbC are partially coherent with the matrix showing the misfit dislocations on every five (002)f layers. It was also found that the pre-warm rolling prior to the aging refines the NbC carbides into sizes as small as about 5 nm and produces a homogeneous distribution. It was statistically clarified that the deformation microstructures of the Fe-Mn-Si-based alloys containing finely dispersed NbC carbides exhibit nano-sized monopartial stacking martensite plates, similar to those of the conventional Fe-Mn-Si-based alloys subjected to the training treatment. These microstructural features are considered to improve the shape memory properties of the alloys.
