Elevated temperature properties of Mg–14Li–B particulate composites

The creep behavior of Mg–14Li particulate composites containing 0,10,20, and 30 vol. % boron particles was evaluated from 230 to 280°C. The results reveal that the creep strength of the particulate composite is increased by a factor of eight over the Mg–14Li matrix with the addition of 30 vol. % boron. The body-centered cubic (bcc) Mg–14Li alloy is shown, however, to be much weaker than hexagonal close-packed (hep) pure magnesium. This difference is attributed to the high rate of atom mobility in the open structure of the Mg–14Li bcc alloy. It is predicted that a Mg–6Li–30B particulate composite, containing an hep matrix structure, will have a higher specific strength at 250°C than the new experimental aluminum base–high iron alloys prepared by rapid solidification processing.