Comment on shear-rotation mechanism for martensitic transformations

The "shear-rotation mechanism" for f.c.c.→b.c.c.(b.c.t.) martensitic transformation is further discussed in this paper. Although "shear-rotation mechanism" involves some valuable ideas which is based on the Nishiyama's model, the concept of "rotation" in "shear-rotation mechanism" may not be consistent with the general definition in crystallography. In addition, the mathematical expression of this mechanism is questionable. Furthermore, a detailed mathematical analysis given in the present paper indicates that the nature of "shear-rotation mechanism" is equivalent to the first two steps of Nishiyama's model, I.e. It is an invariant line strain (ILS) rather than an invariant plane strain (IPS). In other words, it is difficult to obtain the IPS based on the "shear-rotation mechanism" even though the isotropic contraction is involved. Therefore, a new method should be developed to explain the IPS based on Nishiyama's model.