Effect of grain refinement on the mechanical and shape memory properties of Cu-Al-Mn base alloys

The effect of grain refinement on the mechanical and shape memory (SM) properties of the β phase Cu-Al-Mn alloys with L21, structure were investigated by optical microscopy, scanning electron microscopy, differential scanning calorimetry and tensile-testing. Additions of V or Cr to the Cu-Al-Mn ternary alloy in amounts over 0.5at.%V or 1at.%Cr were effective in refining the β phase grain sizes to less than 200 µm. The Ms temperature decreased with increasing V or Cr content, obeying the Hall-Petch type relation with the β-grain size. The mechanical properties were improved, but the SM and pseudoelastic properties were not improved by grain refinement