Effects of Residual Gases on Tribo-Chemical Reaction of Nickel in Hydrogen Gas Atmosphere

Abstract

The mechanisms of tribo-chemical reactions occurring between atmospheric gases and Cu, Fe, and Ni induced by friction were analyzed using XPS combined with a friction test system. For Ni, the friction coefficient measured in hydrogen was comparable to that measured in air. On the basis of results of the friction test performed by varying the partial pressure of hydrogen, the authors proposed a reaction model to describe the phenomena observed, and analyzed the role of the hydrogen and trace gases. The results indicated that water as well as hydrogen had an important role in the tribo-chemical reaction of Ni in a hydrogen gas environment.

Keywords

• friction
• hydrogen
• nickel
• x-ray photoemission spectroscopy
• water
• tribo-chemical reaction