JME_V2_N4_RP2 D. Afshari M. Sedighi Z. Barsoum Journal on Mechanical Engineering 2249 - 0744 2 4 6 9 Residual Stress, X-Ray Diffraction, Spot Weld, Aluminum Alloys In this study, residual stress measurement in resistance spot welded aluminum joint is investigated. A pair of 2 mm thickness aluminum 6061-T6 sheets are prepared and welded according to the American Welding Society (AWS) standard. Due to the small dimensions of nugget and heat affected zone in this process, the X-ray diffraction method utilized for residual stress measurement. The results show that the outside areas of the nugget are influenced by the preliminary sandpaper grinding process. Also, residual stress measurement on the edge of the nugget shows a wide deviation which is due to the changes in surface height. The results imply that, the residual stress measurements in resistance spot welded joints are limited within nugget area for which the grinding stresses were relaxed by the high temperature during welding. The observed residual stresses at this zone show tensile stresses at surface which increase from center toward the edge of the nugget. August - October 2012 Copyright © 2012 i-manager publications. All rights reserved. i-manager Publications http://www.imanagerpublications.com/Article.aspx?ArticleId=1984