The effect of Co on the oxysulfidation behaviour of vulcanized brass s
heets has been studied by means of auger depth profiling combined with
the statistical technique Maximum Likelihood Common Factor Analysis (
MLCFA). The chemical information, inherently present in the strongly o
verlapping auger spectra, could be extracted by MLCFA and, hence, allo
wed a detailed chemical characterization of the oxysulfidation layer a
t the rubber brass interface. From this study it follows that Co acts
as a selective diffusion barrier, promoting the growth of CuxS at the
rubber interface, while retarding the ZnS production. Some aspects of
this behaviour can lead to a better understanding of the oxysulfidatio
n mechanism in the presence of ternary elements.