This research has two related goals, as follows: continued improvement of the high resolution scanning ion microprobe analysis system and its application to improved understanding of aluminum-lithium alloys. The program is directed towards quantitative determination of the distribution of lithium in aluminum-lithium alloys. It requires initial studies on the spatial resolution of secondary ion mass spectrometry, creation of standards for the lithium and aluminum ion signal ratios as a function of lithium concentration, and determination of detectability of lithium in aluminum-lithium alloys. Aluminum- lithium alloys will be examined to measure the distribution of lithium in second phases, at grain boundaries, and at fracture surfaces to gain understanding of the segregation of lithium in these alloys. Results will be correlated with transmission electron microscopy studies at Lehigh University. Phase stability in the system will be determined using samples undergoing ion implantation and ageing treatments. Results will be correlated with studies using neutron depth profiling at the National Bureau of Standards.
