Microstructure, phase transitions and mechanical properties of Ni₅₀Mn₃₄In_16-yCo_y alloys

The influence of partial substitution of Co for In on the microstructure, phase transitions and mechanical properties of Ni₅₀Mn₃₄In₁₆ alloys are investigated in detail. The results show that Ni₅₀Mn₃₄In₁₄Co₂ alloy is of single phase, and the Co-rich second phase starts to precipitate with an amount more than 3 at.%. The phase transition temperatures were increased in samples with 2-4 at.% cobalt, and decreased with more than 5 at.% cobalt addition. This alteration is mainly due to the modification of the matrix compositions. Moreover, the compressive strength and maximum compressive strain were enhanced by the substitution of Co for In.