Revealing the lithium content in aerospace alloys

Gatan instrument used

Cipher^® – The first and only system that quantitatively reveals the distribution of lithium in scanning electron microscopes

Background

Development of lightweight metals with high specific strength and improved plasticity remains of high priority to the automotive, aerospace, and defense industries where reducing mass is requisite to increasing fuel efficiency and reducing emissions. Accordingly, magnesium-lithium (Mg-Li) base alloys present tremendous potential due to the potential for a reduction in density by 30%. Mg-Li alloys are unique in that three different crystal structure configurations can result depending on the lithium concentration. The hexagonal close-packed (HCP) α phase (10.3 wt. % Li) and a duplex α + β (5.7–10.3 wt. % Li) phase. Despite significant interest in these alloys since the early 1930s, a lack of microanalytical tools suitable for studying Li-containing materials prevented significant adoption as the mechanisms of phase stabilization using aluminum and hardening using rare earth (RE) elements remained unclear.