Accommodation of transformation strain at cell interfaces during cubic to tetragonal transformation in a Ni-25at.%V alloy

The ordering transformation in a stoichiometric Ni-25at.%V alloy involves a cubic (A1) to a tetragonal (DO22) transformation. The microstructure essentially comprises cells (or colonies) of transformation twins corresponding to different variants of the ordered phase. Whereas it is well established that the formation of transformation twins reduces the strain energy associated with such cubic to noncubic transformations, the role of the interface separating two contiguous cells in further reducing the strain energy is generally overlooked. This paper presents some evidences of accommodation of strain at and in the vicinity of the intercell interfaces.