Force measurement-based discontinuity detection during friction stir welding

Journal Article · Thu Feb 23 00:00:00 EST 2017 · Journal of Manufacturing Processes

DOI:https://doi.org/10.1016/j.jmapro.2017.01.007· OSTI ID:1373910

Shrivastava, Amber ^[1]; Zinn, Michael ^[1]; Duffie, Neil A. ^[1]; Ferrier, Nicola J. ^[2]; Smith, Christopher B. ^[3]; Pfefferkorn, Frank E. ^[1]

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1. The Univ. of Wisconsin, Madison, WI (United States)
2. Argonne National Lab. (ANL), Lemont, IL (United States)
3. Wolf Robotics LLC, Fort Collins, CO (United States)

Here, the objective of this work is to develop a method for detecting the creation of discontinuities (i.e., voids, volume defects) during friction stir welding. Friction stir welding is inherently cost effective, however, the need for significant weld inspection can make the process cost prohibitive. A new approach to weld inspection is required in which an in situ characterization of weld quality can be obtained, reducing the need for postprocess inspection. To this end, friction stir welds with subsurface voids and without voids were created. The subsurface voids were generated by reducing the friction stir tool rotation frequency and increasing the tool traverse speed in order to create “colder” welds. Process forces were measured during welding, and the void sizes were measured postprocess by computerized tomography (i.e., 3D X-ray imaging). Two parameters, based on frequency domain content and time-domain average of the force signals, were found to be correlated with void size. Criteria for subsurface void detection and size prediction were developed and shown to be in good agreement with experimental observations. Furthermore, with the proper choice of data acquisition system and frequency analyzer the occurrence of subsurface voids can be detected in real time.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC); National Science Foundation (NSF); University of Wisconsin System
• Grant/Contract Number: AC02-06CH11357
• OSTI ID: 1373910
• Alternate ID(s): OSTI ID: 1416205
• Journal Information: Journal of Manufacturing Processes, Vol. 26, Issue C; ISSN 1526-6125
• Publisher: Society of Manufacturing Engineers; Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

47 OTHER INSTRUMENTATION
Aluminum
Discontinuity detection
Force measurement
Friction Stir Welding