Phase Stability and Mechanical Properties of Multi-Phase Alloys Based on the B2 CoA1 and the E2 1 Co 3 AlC

The Co-Al-C ternary phase diagram has been experimentally examined for the Co-corner with a particular interest in phase relations among B2 type intermetallic compound, the E2{sub 1} type Co{sub 3}AlC, and cobalt primary solid solution, denoted as (Co). Reaction scheme, liquidus surface, isothermal sections and isoplethals at constant concentration were determined. Mechanical properties of the B2/E2{sub 1}/(Co) three-phase alloys were investigated by compression tests carried out at a temperature range from 77 to 1,273 K, and by tensile tests at room temperature. It has been revealed that both excellent ambient temperature ductility and sufficient high temperature strength can be achieved by proper choice of alloy compositions.