Due to fact that Cu-based alloys are very sensitive to the thermal treatments, in scanning electron microscopy and X-ray diraction observations, according to the dierent quenching techniques Cu26.04%Zn4.01%Al alloys can display dierent product phases such as martensite and precipitation. Rapidly cooling sample was formed as M18R structure from the ordered DO3 phase and in the monoclinic case, β = 89.1 • determined for sample. It was seen that a α-precipitation (fcc) phase in the matrix is slowly cooling.