Applying Auger electron spectroscopy to the Li depletion in heat treated Al–Li sheets

Solution heat treatments of Al–Li alloys are necessary to obtain their optimum mechanical properties. Such treatments, however, cause undesired processes such as heavy oxidation, Li depletion and pore formation near the surface. One tool for the investigation of cross-sections of heat treated Al–Li sheets is Auger electron spectroscopy AES.. The low sensitivity of this method for Li can be overcome by chemisorbing oxygen as a species ‘decorating’ Li-rich areas whereby additionally the 39 eV Li signal is enhanced. Depending on the shape of pores and the geometry of the experimental setup, Li enrichments in pores can be made detectable by Ar-ion sputtering. Despite some limitations the combination of these methods should make it possible to apply scanning Auger spectroscopy on the investigation of Al–Li alloys with the advantage of a high lateral resolution. q1999 Elsevier Science B.V. All rights reserved.