Patent ID: 8637161

Claim:
A coated article, comprising: a composite substrate made from carbon fiber and zirconium diboride; a chromium layer deposited on the substrate; a chromium diffusing layer formed on the substrate and adjacent to the chromium layer, the chromium diffusing layer comprising carbon-fiber, zirconium-diboride ceramic phase, chromium metal phase and chromium-carbon phase; a chromium-nitrogen layer deposited on the chromium layer; and an iridium layer deposited on the chromium-nitrogen layer opposite to the chromium layer; wherein the chromium-nitrogen layer comprises a first chromium-nitrogen layer and a second chromium-nitrogen layer, the first chromium-nitrogen layer abuts the chromium layer, the second chromium-nitrogen layer abuts the iridium layer, the atomic nitrogen content in the first chromium-nitrogen layer increases from a surface of the first chromium-nitrogen layer near the chromium diffusing layer to a opposite surface of the first chromium-nitrogen layer near the second chromium-nitrogen layer, the atomic nitrogen content in the second chromium-nitrogen layer decreases from a surface of the second chromium-nitrogen layer near the first chromium-nitrogen layer to a opposite surface of the second chromium-nitrogen layer near the iridium layer.