ABSTRACT
Refractory metal and alloy coatings have applications at elevated temperatures where improvements in wear corrosion, oxidation, or erosion resistance are required. Chromium can be electrodeposited from aqueous electrolyes; however, to electrodeposit other refractory metals, molten salt electrolytes are normally required. Physical vapour deposition processes such as ion plating and magnetron sputtering are methods whereby refractory metals and alloys can be deposited at temperatures below steel tempering temperatures. Metal coatings deposited at normal incidence at higher deposition rates or by alternate coating and argon atom beam bombardment had increased surface faceting, no columnar grain growth, and virtually no nodular growth defects. Alloy coatings deposited at parallel incidence by alternate deposition of two metals, which had limited solubility in each other and different atomic radii, together with argon atom beam bombardment, produced dense coherent coatings.
