Structural Analysis of the Surface Layers of Polished Titanium.

Abstract

Structures and properties of buff polished (BP) and mechano-chemically polished (MCP) titanium surfaces were investigated by using surface sensitive analysis. Optical micrographs of metal/scale cross-sections of titanium samples revealed a thick modified layer in the titanium surface region that is affected by the action of BP and MCP surface treatments. High density and wide distribution of hydrogen have been found in the thick modified layers by means of elastic recoil detection analysis (ERDA), and the chemical states of the hydrogen such as hydroxides were observed by using X-ray photoelectron spectroscopy (XPS) and electron stimulated desorption (ESD) with deuterium deposited on sample surfaces. Oxide layers on titanium surfaces of BP and MCP treatments were characterized using XPS and Auger electron spectroscopy (AES). The oxide layers had mixed up the structures of Ti, O and C, although thick oxygen and hydroxides layers were covered with thin carbon contamination and TiO2 layers. The modified layers have shown porous structures in terms of molecular scale.