SOLIDIFICATION CHARACTERISTICS AND MICROSTRUCTURAL EVOLUTION OF Zn-1.26 wt.% Al ALLOY

WOS: 000301236300007Zn-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 (G = 1.94-5.15 K/mm) and with a constant temperature gradient (G = 5.15 K/mm) in a wide range of growth rates (V = 8.3-500 mu m/s) with a Bridgman-type directional solidification furnace. Microstructure parameters, the primary dendrite arm spacing (lambda(1)), secondary dendrite arm spacing (lambda(2)) and dendrite tip radius (R), were measured and expressed as functions of G and V by using a linear regression analysis method. It was found that the values of lambda(1), lambda(2) and R decrease with increasing values of V and G. The experimental results were compared with the main predictive theoretical and experimental works for dendritic spacings.Nigde University Scientific Research Project Unit [FEB 2009/02]This project was supported by the Nigde University Scientific Research Project Unit under Contract No: FEB 2009/02. The authors are grateful to the Nigde University Scientific Research Project Unit for its financial supports