The effect of Co addition on the order-disorder transition temperature, Ms temperature, ductility, hardness and the shape memory properties of ductile Cu-Al-Mn shape memory (SM) alloys was investigated by differential scanning calorimetry (DSC), cold-rolling, and tensile test techniques. It was found that the addition of Co to the Cu-Al-Mn alloys stabilized the B2 phase and decreased the Ms temperature. In the Cu71Al17Mn10Co2 alloy, the B2 to L21 ordering transformation was suppressed by quenching from 900 °C and the retained B2 parent phase transformed to the 6 M martensite. In several other alloys of this system, the presence of the CoAl (B2 type) precipitate phase was observed. Even though the CoAl precipitate caused a decrease in the cold-workability and the degree of elongation, it nonetheless improved the SM and pseudoelastic (PE) properties of the alloy by solid solution or/and precipitation hardening.
|Number of pages
|Materials Science Forum
|Published - 2000
|Proceedings of the 1999 International Symposium and Exhibition on Shape Memory Materials (SMM'99) - Kanazawa, Jpn
Duration: 1999 May 19 → 1999 May 21