Investigation of mechanical, electrical, and thermal properties of a Zn-1.26 wt% Al alloy
Zn-1.26 wt% Al alloy was directionally solidified upward with a constant growth rate (V = 16.6 mu m/s) in a wide range of temperature gradients (1.94-5.15 K/mm) and with a constant temperature gradient (G = 5.15 K/mm) in a wide range of growth rates (8.3-500 mu m/s) with a Bridgman-type directional solidification furnace. The microhardness (HV) and tensile strength (sigma) of alloy were measured from directionally solidified samples. The dependency of the microhardness, tensile strength for directionally solidified Zn-1.26 wt% Al alloy on the solidification parameters (G, V) and microstructure parameters (lambda(1), lambda(2)) were investigated and the relationships between them were experimentally obtained using regression analysis. According to present results, the microhardness and tensile strength of directionally solidified Zn-1.26 wt% Al alloy increase with increasing solidification processing parameters and decrease with the microstructure parameters. Variations of electrical resistivity (rho) with the temperature in the range of 300-650 K were also measured using a standard dc four-point probe technique for cast samples. The enthalpy of fusion and specific heat for same alloy was also determined by means of differential scanning calorimeter (DSC) from heating trace during the transformation from solid to liquid.