Revealing a Transformation-Induced Plasticity (TRIP) Phenomenon in a Medium-Entropy Alloy

Abstract

A transformation-induced plasticity phenomenon in Fe 65 (CoCrMnNi) 35 medium-entropy alloy was investigated. According to the X-ray diffraction patterns, the as-cast specimen contains a single-phase face-centered cubic (fcc), while low-temperature annealing at 500 °C and 600 °C leads to the introduction of a body-centered cubic (bcc) phase as a secondary phase. Further increment of the annealing temperature to above 700 °C eliminates the bcc phase, and the microstructure was found to contain a single-phase fcc. At 20% true strain, an fcc-to-bcc phase transformation is observed; whereas, at 28% true strain, an fccto-hcp phase transformation takes place as an additional deformation mechanism. This strain-induced phase transformation phenomenon leads to improved tensile properties of this alloy.