Causal Factors of Weld Porosity in Gas Tungsten Arc Welding of Powder Metallurgy Produced Titanium Alloys

Journal Article · Tue Jan 01 00:00:00 EST 2013 · Journal of the Minerals Metals & Materials Society (JOM)

DOI:https://doi.org/10.1007/s11837-013-0592-5· OSTI ID:1078173

Muth, Thomas R ^[1]; Yamamoto, Yukinori ^[1]; Frederick, David Alan ^[1]; Contescu, Cristian I ^[1]; Chen, Wei ^[1]; Lim, Yong Chae ^[1]; Peter, William H ^[1]; Feng, Zhili ^[1]

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1. ORNL

ORNL undertook an investigation using gas tungsten arc (GTA) welding on consolidated powder metallurgy (PM) titanium (Ti) plate, to identify the causal factors behind observed porosity in fusion welding. Tramp element compounds of sodium and magnesium, residual from the metallothermic reduction of titanium chloride used to produce the titanium, were remnant in the starting powder and were identified as gas forming species. PM-titanium made from revert scrap where sodium and magnesium were absent, showed fusion weld porosity, although to a lesser degree. We show that porosity was attributable to hydrogen from adsorbed water on the surface of the powders prior to consolidation. The removal / minimization of both adsorbed water on the surface of titanium powder and the residues from the reduction process prior to consolidation of titanium powders, are critical to achieve equivalent fusion welding success similar to that seen in wrought titanium produced via the Kroll process.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1078173
• Journal Information: Journal of the Minerals Metals & Materials Society (JOM), Vol. 65, Issue 5; ISSN 1047--4838
• Country of Publication: United States
• Language: English

Related Subjects

Gas Tungsten Arc Welding
Powder Metallurgy
Titanium Alloys