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

A transformation-induced plasticity phenomenon in Fe65(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℃and 600℃leads to the introduction of a body-centered cubic(bcc)phase as a secondary phase.Further increment of the annealing temperature to above 700℃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.