ON THE TRANSFORMATION CHARACTERISTICS OF LA141A (MG-LI-AL) ALLOY

The use of Magnesium-Lithium LA141A-T7 alloy for nonstructural or seco ndary structural aerospace applications was abandoned mainly because o f the loss in strength above room temperature. At temperatures of 90 - 150 degrees C the ultimate strength decreased by about 50% from the r oom temperature strength. Two processing methods were used in this stu dy in an effort to retain the strength at the intermediate temperature s. The first method consisted of a series of cold rolling and annealin g treatments. The cold rolling was employed in the longitudinal, trans verse and 45 degrees directions. The second method was similar to the first but included a solution treatment: at 315 degrees C. Both method s resulted in a retention of strength at the elevated temperatures by stabilizing the structure and inhibiting recrystallization.