Abstract
Magnesium alloy AS21 reinforced by short Saffil fibres was thermally cycled between room temperature and increasing upper temperature of the thermal cycle. The strain amplitude dependence of the logarithmic decrement was measured after the thermal treatment.
An increase of the logarithmic decrement was observed after the thermal treatment. The thermal cycling response is characterised by thermal stresses that can be relaxed by anelastic as well as microplastic strain.
Even moderate temperature changes may produce the thermal stresses that exceed the yield stress of the matrix, and consequently, generating new dislocations at the interfaces between the matrix and the fibres. Thermal fatigue (microstructure changes, matrix plastic deformation) is observed.
The processes are discussed.