Degradation of the mechanical properties of a Mg–Li–Al composite at elevated temperatures studied by the stress relaxation technique

Metal matrix composites LA40 and LA43 were deformed in compression. Sequential stress relaxation tests were performed at temperatures from RT up to 200 °C. The duration of the stress relaxation tests was 300 s. The internal stress was determined from the stress relaxation curves using a computer fitting. The results show that the internal stress represents a substantial part of the applied stress. The possible components of the internal stress are discussed.