Martensitic transformation of iron particles embedded in copper matrix during tension in crystals previously deformed on another slip system

Abstract

Martensitic transformation in coherent γ-Fe particles embedded in copper single crystals was investigated in tension at room temperature. Single crystals of a Cu–Fe alloy, which contained metastable γ-Fe particles, were pre-strained in an easy glide region (slip in primary system) followed by tension in different slip systems. Slip in secondary systems results in the latent hardening ratio of about unity irrespective of the operating latent systems, which is different from the results for pure Cu or single phase copper alloys. In contrast, the volume fraction of transformed α-Fe particles strongly depends on the deformation history, as well as the active latent system. The transformation kinetics becomes faster in the samples subjected to the secondary deformation. The highest rate of transformation was for the latent system C5. The latter is discussed in terms of the possible influence of matrix dislocations on the dilatational component of the transformation shape strain.