Phase decomposition in a β Cu–Zn–Al–Ti–B shape memory alloy

A β Cu–Zn–Al, with and without TiB addition as grain refining, shape memory alloy has been investigated with detail in order to evaluate the influence of this grain refiner on some alloy properties. For Cu–Zn–Al–Ti–B, on isothermal aging in the range of 523–773 K, the β phase was found to decompose by the precipitation of γ phase followed by α phase and eutectoid decomposition. The γ precipitate volume fraction evolution as a function of aging time has been determined and the TTT diagram for the precipitation of both γ and α phases has been constructed. Besides, nonisothermal aging behavior has been investigated by means of differential scanning calorimetry for Cu–Zn–Al and Cu–Zn–Al–Ti–B alloys.