Measurements of electrical and thermal properties with growth rate, alloying elements and temperature in the Al–Si–X alloys

Abstract

In this work, effect of alloying elements (X = Cu, Co, Ni, Sb and Bi) and growth rates on the microstructure, physical properties (electrical resistivity, enthalpy and specific heat) of the directionally solidified Al–Si eutectic alloy have been investigated. Al–12.6Si–2X (wt. %) samples were prepared using metals of 99.99% high purity in the vacuum atmosphere. These alloys were directionally solidified under constant temperature gradient, G (7.80 K/mm) and different growth rates, V (8.3–166.0 μm/s). Flake spacing (λ) and electrical resistivity (ρ) were measured from the solidified samples. The variation of electrical resistivity with temperature in the range of 300–500 K for alloying elements in the Al–Si eutectic cast alloy was also measured. The enthalpy of fusion (ΔH) and specific heat (Cp) for the same alloy were determined by a differential scanning calorimeter from the heating curve during the transformation from solid to liquid.