Thermal conductivity and electrical resistivity dependences on growth rate in the directionally solidified Al–Cu–Ni eutectic alloy

Abstract

The thermal conductivity and electrical resistivity dependences on growth rate in the directionally solidified Al-Cu-.Ni eutectic alloy (Al-32.5 wt%Cu-%1 wt.Ni) were investigated. For this purpose, the Al-Cu-.Ni eutectic alloy was solidified at a constant temperature gradient of 4.93 K mm−1 with different growth rates, V = 9.25–2056.68 μm s−1 by a Bridgman type directional solidification furnace. The thermal conductivity (K) and electrical resistivity (ρ) of the Al-Cu-Ni alloy solidified with different growth rates were measured with the longitudinal heat flow method and DC four−point probe technique at room temperature. The dependences of K and ρ on V for directionally solidified Al-Cu-Ni eutectic alloy were experimentally obtained by linear regression analysis. Finally, the specific heat difference between solid and liquid phases (ΔCP) and enthalpy of fusion (ΔH) for Al-32.5 wt%Cu-%1 wt.Ni alloy were determined by means of differential scanning calorimetry (DSC) at its melting temperature.