Influence of Heating and Cooling Rate on Phase Transformations Temperatures in EV31A Magnesium Alloy

Following article summarizes results of the researches concerning influence of heating and cooling rate on the phase transformations temperatures in EV31A magnesium alloy. Particular attention has been paid to calibration aspects of the temperature measurement as well as cooling and heating rates in protective atmosphere. The researches were conducted on Multi HTC calorimeter, provided by Setaram company. The samples were heated up to liquidus temperature with controlled rates of: 2.5°C/min, 5°C/min, 10°C/min, 15°C/min and 20°C/min. Just after melting, the specimens were cooled with the same rates. Equilibrium temperatures of phase transformations were calculated by extrapolation to zero heating/cooling rate. Considerable difference between melting point (during heating) and solidification temperature (during cooling) were noticed on cooling/heating curves. The alloy specific heat has also been calculated.