In-situ characterization of MgLi composite materials by means of AES and factor analysis

During manufacture of -Al₂O₃ fibre reinforced MgLi alloys the high mobility and reacitivity especially of the Li metal can cause damage of the fibres and loss of the good mechanical behaviour. Because of the low fibre diameter (2 to 5 m), and the necessity to detect Li, laterally highly resolved Auger electron spectroscopy was used to study the fibre-matrix-interaction. The measurements were performed at sample surfaces, which had been uncovered by in-situ fracture in the UHV apparatus. Due to the bad signal/noise ratio (which was tolerated to achieve high lateral resolution) and the overlapping spectral features, and in order to make an attempt to classify the large amount of spectra obtained, factor analysis in conjuction with cluster analysis was used in the interpretation of AES data. So it was possible to detect the chemical species which are responsible for the apperance of the experimental spectra and to draw conclusions concerning the fracture morphology (inter granular, trans granular).Dedicated to Professor Dr. rer. nat. Dr. h.c. Hubertus Nickel on the occasion of his 65th birthday