Grain refinement of copper based alloys using ECAP

Equal-channel angular pressing (ECAP) was conducted to achieve grain refinement in a series of Cu-based alloys having either a single-phase or a two-phase condition. The phase condition of the alloys was controlled through the introduction of Zn as an alloying element and Zr was also added to provide some thermal stability of the ultrafine-grained structures. Microstructures were observed by optical microscopy and transmission electron microscopy and the tensile properties of the as-pressed alloys were examined at elevated temperatures. It is shown that superplasticity is attained under optimum conditions in both the single-phase and the two-phase alloys after processing by ECAP.