Development of Amorphous Alloy Surface Coatings as Replacement for Chromate Technology

Electrodeposited chromium films have played a key role in the advancement of industrial technology over the past century. Unfortunately, such coatings have a critical problem, namely, the electroplating solution involves hexavalent Cr, which is a severe occupational and environmental hazard. We have produced a proprietary refractory amorphous metallic film that has a nanoindentation hardness approximately 10 times harder than electroplated Cr, has withstood temperatures of 500oC for 18 hours without devitrification, and is potentially at least as good, if not better, in corrosion resistance. The metallic glass structure and stability of the alloy has been verified by high-resolution synchrotron radiation scattering methods. There are several goals that are envisaged in Phase I of this proposal: 1) We need to further develop the proprietary alloy to enable us to make prototype coatings on parts processed with an industrial scale PVD chamber. 2) We will need to investigate those parameters that must be controlled to ensure adhesion to a wide variety of technical surfaces including metals, semiconductors, ceramics, and plastics. 3) The proprietary alloy is potentially the precursor of an entire class of multi-component amorphous metallic glass coatings that can be processed by low cost industrial PVD technology.