Surface hardening of Ti-6Al-4V alloy by hydrogenation

Journal Article · Tue Oct 01 00:00:00 EDT 1991 · Scripta Metallurgica; (United States)

DOI:https://doi.org/10.1016/0956-716X(91)90025-V· OSTI ID:5879605

Wu, T I ^[1]; Wu, J K ^[2]

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1. Dept. of Materials Engineering, Tatung Inst. of Technology, Taipei (TW)
2. Dept. of Marine Engineering, Materials Program, National Taiwan Ocean Univ., Keelung (TW)

Thermochemical processing is an advanced method to enhance the fabricability and mechanical properties of titanium alloys. In this process hydrogen is added to the titanium alloy as a temporary alloying element. Hydrogen addition lowers the {beta} transus temperature of titanium alloy and stabilizes the {beta} phase. The increased amount of {beta} phase in hydrogen-modified titanium alloys reduces the grain growth rate during eutectoid {beta} {yields} {alpha} + hydride reaction. Hydrogen was added to the titanium alloy by holding it at a relatively high temperature in a hydrogen gaseous environment in previous studies. Pattinato reported that Ti-6Al-4V alloy can react with hydrogen gas at ambient temperature and cause a serious hydrogen embrittlement problem. The hydrogen must be removed to a low allowable concentration in a vacuum system after the hydrogenation process. The present study utilized an electrochemical technique to dissolve hydrogen into titanium alloy to replace the hydrogen environment in thermochemical processing. In this paper microstructures and hardnesses of this new processed Ti-6Al-4V alloy are reported.

• OSTI ID: 5879605
• Journal Information: Scripta Metallurgica; (United States), Vol. 25:10; ISSN 0036-9748
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
MECHANICAL PROPERTIES
THERMOCHEMICAL PROCESSES
HYDROGEN
DISSOLUTION
TITANIUM ALLOYS
VANADIUM ALLOYS
AMBIENT TEMPERATURE
BRITTLENESS
CONCENTRATION RATIO
ELECTROCHEMISTRY
FABRICATION
GASES
GRAIN GROWTH
HARDNESS
HYDROGEN ADDITIONS
INHIBITION
MICROSTRUCTURE
STABILIZATION
TEMPERATURE DEPENDENCE
ALLOYS
CHEMISTRY
CRYSTAL STRUCTURE
ELEMENTS
FLUIDS
NONMETALS
360101* - Metals & Alloys- Preparation & Fabrication
360102 - Metals & Alloys- Structure & Phase Studies
360103 - Metals & Alloys- Mechanical Properties