Abstract
Close relationship is recognized between phase boundary and electron concentration in high strength brass castings. The ratio of the requisite content of zinc for a characteristic electron concentration to that of an alloying element in a binary copper alloy is defined as a zinc factor, which is a useful index to control the microstructures of high strength brass castings. Zinc equivalents of several alloying elements calculated from zinc factors were found to be in good agreement with those reported by previous works, except those of transition elements.
