Compressive creep resistance of Mg–14Li–Al–MgO/Mg 2 Si composites

Abstract

Compressive creep tests have been carried out on Mg–14Li–Al–MgO/Mg₂Si composites containing about 0, 5, 10 and 15 vol.-%MgO/Mg₂Si particulates in the temperature range of 100–190°C and under different pressures in the range of 40–70 MPa. The results reveal that the creep resistance of the particulate composites is increased with increasing content of MgO/Mg₂Si particulate. After the addition of SiO₂, considerable improvement of creep resistance can be achieved in Mg–14Li–Al–MgO/Mg₂Si composites. The creep data for these composites could be correlated using an empirical equation ϵ´_s = Aσⁿexp (−Q/RT) where n is 7·38–9&middot42 and Q is about 109·9–135&middot2 kJ mol⁻¹. The compressive creep rate is controlled by the diffusion of Li and the dislocation climb based on the results of the present study.