Control of Electrical and Thermal Properties by 8 vol% Al<sub>2</sub>O<sub>3</sub> Distribution States in Zn–50Sn for AC-Low Voltage Fuses

Abstract

The addition of 8 vol% Al2O3 in Zn­50mass%Sn, was carried out for the control of electrical and thermal properties, for Pb-free fuse elements used in electric power line. The distribution-control of Al2O3 particles in Zn­50Sn was carried out by the varying process parameters such as the temperature and period for Al2O3-addition and -stir in its melt or semi-solid. Homogeneous and heterogeneous Al2O3-distributions were achieved in microstructure consisting of primary Zn and eutectic, which meant the location of Al2O3 in both regions and only eutectic in constituent phases, respectively. The temperature dependence of specific resistivity, thermal conductivity, specific heat and density was measured for electrical and thermal calculations to obtain the temperature distribution in fuses. The values on their properties were determined depending on Al2O3 distributed states in alloys. Both the melt and un-melt down performance for AC-low voltage fuse elements could be satisfied on both Zn­50Sn alloys with different distribution of Al2O3, and the superior performance was shown in the homogeneously Al2O3 distributed alloy. [doi:10.2320/matertrans.MBW201303]