[en] The mechanical properties of ACuZinc5TM alloys are influenced by the fraction solid of the primary epsilon (e) phase and their interrelations with the eta (η) phase. In this study the primary epsilon phase fraction results from cooling conditions similar to that applied in different casting processes have been measured. Additionally an analysis was made from the morphology's changes and from the thermal analysis results to suggest the probably adequate moment to apply stirring in semisolid metal processing. From these results it is possible to design experimental thermal cycles to obtain an adequate distribution of e and . phases in the end castings microstructure. (Author) 21 refs.