Production and Characterization of Extremely Corrosion Resistant Chromium-Metalloid Alloys

A series of extremely corrosion resistant chromium-metalloid alloys have been investigated. Glassy Cr72P28, Cr87Pi3, Cr70B30, and mixed-phase glassy-nanocrystalline Cr93P7 were fabricated by thin-film processing. These binary alloys exhibit extraordinary corrosion resistance when compared with pure crystalline chromium. In 12M HC1 chromium dissolves rapidly, ca. 1 g/cm2/day, while negligible corrosion of the chromium-metalloid alloys occurred, ca. ˂10-7 g/cm2/day. X-ray photoelectron spectroscopic analysis of the exposed specimens revealed a strong enrichment of phosphate in the passive film and phosphorus at the metal-film interface. The interaction of the redox chemistry of chromium and the metalloids is responsible for the superior corrosion resistance. © 1991, The Electrochemical Society, Inc. All rights reserved.