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Effect of Pin Tool Shape on Metal Flow During Friction Stir WeldingIt has been shown that metal moves behind the rotating Friction Stir Pin Tool in two separate currents or streams. One current, mostly on the advancing side, enters a zone of material that rotates with the pin tool for one or more revolutions and eventually is abandoned behind the pin tool in crescent-shaped pieces. The other current, largely on the retreating side of the pin tool is moved by a wiping process to the back of the pin tool and fills in between the pieces of the rotational zone that have been shed by the rotational zone. This process was studied by using a faying surface copper trace to clarify the metal flow. Welds were made with pin tools having various thread pitches. Decreasing the thread pitch causes the large scale top-to-bottorn flow to break up into multiple vortices along the pin and an unthreaded pin tool provides insufficient vertical motion for there to be a stable rotational zone and flow of material via the rotational zone is not possible leading to porosity on the advancing side of the weld.
Document ID
Acquisition Source
Marshall Space Flight Center
Document Type
Preprint (Draft being sent to journal)
McClure, J. C.
(Texas Univ. El Paso, TX United States)
Coronado, E.
(Texas Univ. El Paso, TX United States)
Aloor, S.
(Texas Univ. El Paso, TX United States)
Nowak, B.
(Texas Univ. El Paso, TX United States)
Murr, L. M.
(Texas Univ. El Paso, TX United States)
Nunes, Arthur C., Jr.
(NASA Marshall Space Flight Center Huntsville, AL United States)
Munafo, Paul M.
Date Acquired
September 7, 2013
Publication Date
January 1, 2002
Subject Category
Mechanical Engineering
Meeting Information
Meeting: 6th International Conference on Trends in Welding Research
Location: Pine Mountain, GA
Country: United States
Start Date: April 15, 2002
End Date: April 19, 2002
Distribution Limits
Work of the US Gov. Public Use Permitted.
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