X-ray diffraction studies on cold-rolled/solid–solution treated α + β Mg–10.2Li–1.2Al–0.4Zn alloy

Abstract

XRD measurements were conducted on an α+β Mg–10.2Li–1.2Al–0.4Zn (LAZ1010) alloy. In 80% cold-rolled plate, strong (0002)α peak intensity is found on the rolling plane, and 2θ values of θ–MgLi2Al peaks are shifted slightly to higher angle, indicating that Mg atoms in θ phase are partly replaced by Al atoms during severe cold-rolling. Solid–solution treated specimens aged at room temperature reach the maximal hardness after ≈20h of aging. XRD tests show that θ precipitates is much smaller in size than α ones, which may be attributed to the hardening phenomenon observed in the solid–solution treated and aged LAZ1010 alloy. During aging, the decrease in hardness of solid–solution treated specimens with severe cold-rolling at its maximal hardness is slower than that without. It is because specimens with severe cold-rolling have abundant nucleus sites and thus have θ precipitates of smaller size.