Thermophysical properties of A201, A319, and A356 aluminium casting alloys

Abstract

Accurate thermophysical property data are of fundamental importance for reliable simulation and design of molten-metal processes. This paper provides specific heat, density, thermal diffusivity, thermal conductivity, and electric resistivity data for three aluminium casting alloys (A210, A319, and A356). The data for each alloy are shown to be self-consistent with respect to transformation temperatures. In addition, the electric resistivity and thermal conductivity data are compared with predictions based on the Wiedemann-Franz-Lorenz law. Experimentally determined Lorenz numbers, L, for these casting alloys have been found to be approximately equal to 95% of the theoretical Lorenz number, L 0 , for solid materials, and equal to L 0 for completely molten samples. Anomalous behavior of the Lorenz number correlation was exhibited in the mushy zone. This is believed to be due to part of the laser-flash energy being consumed in additional melting of the solid phase in mushy-zone material giving rise to lower than expected back surface temperature rises and subsequent decreases in measured values of thermal diffusivity and conductivity in the mushy zone.