Specific Heat, Electrical Resistivity, and Linear Thermal Expansion of the Magnesium Alloy AE42 Measured by Subsecond Pulse Heating

Abstract

Magnesium alloy AE42 (Mg with 4% Al and 2% rare earths) is used for the production of high-temperature creep-resistant castings. Its thermophysical properties are used as input parameters for the numerical simulation of the casting process by finite methods. Measurements of specific heat capacity, electrical resistivity, and linear thermal expansion of the magnesium alloy AE42 in the temperature range from 550 to 840 K by a transient technique are presented and discussed. Tubular specimens were Joule-heated from room temperature up to melting within 500 ms by a large current pulse. The current and the voltage drop along a defined portion of the specimen were measured by a fast precision data acquisition system. Temperature measurements were made with a high-speed broad-band infrared pyrometer. Thermal expansion was measured by a polarized-beam Michelson-type interferometer.