Combining tensile tests and nanoindentation to explore the strengthening of high and medium entropy alloys

Abstract Single-phase multi-component alloys exist for a very wide range of composition, which is still mostly unexplored. To determine the mechanical properties of one new medium entropy alloy (MEA) and to assess the potential of an accelerated testing strategy, the compositions CoCrFeMnNi, (CoCrFeMn)40Ni60 and (CoCrFeMn)8Ni92 were studied. They were processed in homogenized and recrystallized states, characterized by scanning electron microscopy coupled with electron backscattered diffraction and mechanically tested by tensile tests and nanoindentation. It was shown that the (CoCrFeMn)40Ni60 MEA exhibits as high tensile properties as the CoCrFeMnNi high entropy alloy. Not only the mechanical strength but also the ductility are the same in both alloys. Moreover, the uncertainty when comparing nanoindentation on homogenized samples with tensile yield strength was quantified. Knowing that, nanoindentation on homogenized HEA was identified as a powerful tool for fast exploring of chemical compositions and pre-selection of the most promising ones.