Thermal cycling effects in magnesium composites

This paper describes the influence of thermal cycling on changes in the microstructure of Mg composites determined by non-destructive methods. Thermal cycling was performed between room and an upper temperature up to 450 degrees C. The dimensional changes of composite specimens and the acoustic emission activity measured during thermal cycling indicate the creation and motion of dislocations. The strain dependence of the logarithmic decrement measured after thermal cycling can be explained assuming that the microstructure of composites changes due to the creation of new dislocations during thermal cycling.