April AMP_Digital

A D V A N C E D M A T E R I A L S & P R O C E S S E S | A P R I L 2 0 1 9 1 7 determining the upper limit of dry film lubricant weight applied to sheets for the FSW process. This etching technique is also use- ful for examining welds between dis- similar alloys. Figure 5 shows the bond line in a developmen- tal friction stir weld be- tween aluminumalloys 6022 and 5182 made using less than opti- mal conditions. Oxide lines (at the 6022-5128 interface and in 5182) and differences in grain structure are clearly vi- sible. ~AM&P For more information: Elvin Beach, Corporate Materials Laboratory, Worthington Industries Inc., 200 W. Old Wilson Bridge Rd., Colum- bus, OH, 43085, 800. 944.2255, elvin.beach@ worthingtonindustries.com. Note: This article has been adapted from a full length feature in Metallogra- phy, Microstructure, and Analysis (2018) 7:630, DOI 10.1007/s13632-018-0477-7. © ASM International 2018. REFERENCES 1. R.S. Mishra and Z.Y. Ma, Friction Stir Welding and Processing, Mater. Sci. Eng., R 50, p 1-78, 2005. 2. G.K. Padhy, C.S. Wu, and S. Gao, Friction Stir Based Welding and Processing Technologies—Processes, Parameters, Microstructures and Appli- cations: A Review, J. Mater. Sci. Technol., 34, p 1-38, 2018. 3. A.J. Leonard and S.A. Lockyer, Flaws in Friction Stir Welds , Proc. 4th Intl. Symp. on Friction Stir Welding, May 2003. 4. J. Schneider, P. Chen, and A.C. Nunes, Formation of Oxides in the Interior of Friction Stir Welds , https://ntrs.nasa. gov/archive/nasa/casi.ntrs.nasa.gov/ 20160006969.pdf . Fig. 5 — Micrograph of friction stir welded AA6022 (left) and AA5182 (right) sheets of different thicknesses, magnification 50x. Etching reveals a clear oxide line at the weld interface and additional oxide lines in alloy 5182 near the weld root and in alloy 6022 near the weld face (far right side). 500 µm