XPS and SIMS Examination of Alumina Fibres Affected with Mg and MgLi Melt

 Fibre/matrix interfaces in δ-Al2O3/Mg8Li and δ-Al2O3/Mg composites have been investigated using XPS and SIMS analysis of extracted δ-Al2O3 fibres in context with previous XRD observations. Results obtained indicate that in MgLi based composites lithium enters preferentially the interfacial redox reactions producing Li+ ions that occupy vacant cation positions in the defect δ-Al2O3 lattice which results in a strong fibre/matrix interfacial bond. On the other hand, in Mg matrix composites the magnesium oxide appears to be the final reaction product that does not enter the solid state reaction with adjacent δ-Al2O3 fibre during the melt infiltration process, so that only relatively weak interfacial bond is created.