Surface Treatment of Aluminum Oxide Using Atomic Hydrogen Generated by Catalytic Reaction on Heated Tungsten

A surface treatment using atomic hydrogen annealing (AHA) of aluminum oxide (alumina, Al2O3) has been investigated. In AHA, high-density atomic hydrogen is generated on a heated tungsten surface by catalytic cracking reaction. Sintered alumina and thermal sprayed alumina coating surfaces were subjected to AHA. The different behavior in the decrement of carbon and OH groups observed by X-ray photoelectron spectroscopy on the surface of AHA-treated sintered alumina and sprayed alumina was assumed to affect the observed different behavior in the changes of water contact angle by AHA. The difference is thought to be attributed to the different crystal structure of alumina. The chemical reactions of atomic hydrogen with carbon contamination, hydroxyl groups, and adsorbed H2O molecules were also discussed.