Effect of thermally induced relaxation on passivity and corrosion of an amorphous Al–Co–Ce alloy
By Tailleart, N.R.; Huang, R.; Aburada, T.; Horton, D.J. & Scully, J.R.
Published in Corrosion Science
2012
Abstract
The corrosion behavior of Al87Co7Ce6 alloy was investigated in the amorphous as-quenched, amorphous thermally relaxed, and two partially devitrified conditions using AC and DC electrochemical methods combined with high resolution microscopy in the active dissolution and passivity-local breakdown regimes. The best corrosion resistance was observed after relaxation. Intermediate behavior was observed in a partially devitrified treatment that formed small fcc Al particles and intermetallic phases. Further devitrification decreased the corrosion resistance. The amorphous “relaxed conditionâ€?, characterized by EXAFS, is an Al–Co–Ce solid solution with short bond length, high coordination number and reduced free volume compared to the as-quenched amorphous state.