Microstructure refinement and mechanical properties of the NiCoMnIn alloy obtained by arc melting technique from mechanically alloyed powder

Abstract

The Ni45.5Co4.5Mn36.6In13.4 alloy was produced by mechanical alloying during high energy ball milling for 70 h. Then, the powder of NiCoMnIn was cold compressed followed by melting of the green compact by vacuum arc melting technique. The structure and mechanical properties of the obtained alloy were systematically studied. The sub-grain refinement of the Ni45.5Co4.5Mn36.6In13.4 alloy produced by the arc melting from the pre-alloyed powder was observed. It was achieved due to the specific distribution of the γ, parent (L21) and martensite (14 M) phases. The average subgrain size was about 10 μm, which is 100 times lower than grain size observed in the reference bulk sample produced by conventional melting technique. The improvement in mechanical strength from 260 MPa to 1250 MPa for reference and bulk alloy prepared from powders respectively was achieved. Reduced Young’s modulus from nanoindentation experiment was lower in bulk alloy produced from pre-alloyed powder than in reference specimen.