Mechanical Properties of Thin Wall Zinc Alloy Die Castings

Abstract

  Thin wall commercial zinc alloy specimens were cast using 150-kN hot chamber die casting machine with a 1.0mm thickness. The mechanical properties were evaluated by a tensile test and a hardness test. The initial tensile strengths of ZDC2 and ZDC1 are 5% higher than that of ASTM test specimen, respectively. Furthermore, type 3 (ASTM AC43A) and type 4 containing small amount of titanium and beryllium in type 3 of high copper alloys show significant high tensile strength, that increase by 17% higher than that of the ASTM, respectively. Because the thin wall die casting promotes the formation of fine microstructures and simultaneous supersaturation of the solubility of the alloying element in solid solutions owing to rapid solidification. The hardness is closely correlated with the tensile strength for zinc alloy die castings. Natural aging at room temperature for one year decreases tensile strength of the die casting except type 4, however, the decrement rate is smaller than that of the ASTM specimen due to the finer microstructure.