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Effect of Hydrogen Precharging on Mechanical and Electrochemical Properties of Pure Titanium
Author(s) -
Liu Shaopeng,
Zhang Zhong,
Xia Jing,
Chen Yungui
Publication year - 2020
Publication title -
advanced engineering materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 114
eISSN - 1527-2648
pISSN - 1438-1656
DOI - 10.1002/adem.201901182
Subject(s) - materials science , corrosion , titanium , hydrogen , microstructure , metallurgy , precipitation , electron backscatter diffraction , ultimate tensile strength , composite material , chemistry , physics , organic chemistry , meteorology
The electrolytic hydrogen precharging process is used to analyze the influence of hydrogen on the microstructure, corrosion resistance, and mechanical properties of pure titanium. The results demonstrate that two types of titanium hydrides (δ‐TiH x and ϵ‐TiH 2 ) are detected by electron backscatter diffraction (EBSD), and the volume fraction of titanium hydrides, the local strain caused by hydrogen precipitation, and the thickness of hydrides layer increase with the increase in precharging time. It is noteworthy that the formation of hydrides layer has a protective effect on general corrosion, but the local strain caused by hydrides precipitation leads to the destruction of corrosion resistance, as a result the corrosion resistance of pure titanium increases first and then decreases with the increase in hydrogen precharging time. Moreover, with the precipitation of hydrides, the fracture mode changes from ductile failure to duplex‐ and multimode failure, resulting in the decrease in ultimate tensile strength (UTS) and elongation. Therefore, the mechanical and electrochemical properties of the precharged samples first increase and then decrease with the increase in precharging time, reaching their optimum values at 10 h, and the critical precharging time is determined to be 75 h when comparing those properties with pure titanium.