Thermal strain in Mg composites

Abstract

In this paper, the thermal expansion behaviour of Mg-9 vol.% Saffil fibres, ZC63-25 vol.% Saffil fibres and Mg8Li-12 vol. % Saffil fibres has been studied from room temperature to 380 °C. The thermal expansion of pure Mg, ZC63 alloy and Mg8Li alloy was measured in order to calculate the thermal expansion characteristics of the composites free of thermal strain using the rule of mixtures. Using the measured relative elongation and that obtained from the rule of mixtures, the temperature dependences of the dilatational strains could be estimated. Whereas the permanent changes of the specimen length were found after the first thermal cycle for the as-cast composites, only the reversible changes of the dilatational strain were observed after the second and subsequent cycles.