The effect of aging in the β-phase on forward and reverse martensitic transformation temperatures in quenched Cu–Zn–Al alloys

We have investigated the changes of the forward and reverse transformation temperatures in Cu–Zn–Al alloys with aging time in the β-phase after a step-quench by electrical resistivity measurements. With aging in the β-phase, the Ms and Mf temperatures increase and return to the normal values quickly, but the As and Af temperatures still decrease toward the normal values even after the Ms and Mf temperatures reach the normal values. We will discuss briefly the reasons why the reverse transformation temperatures continue to change even after the forward transformation temperatures reach the normal values.