Mechanical and metallurgical characterization of AA6061 friction stir welded joints using microhardness map
(Department of Mining and Metallurgical Engineering,
Amirkabir University of Technology (Tehran Polytechnic), 424 Hafez Ave, Tehran, Iran)
Amirkabir University of Technology (Tehran Polytechnic), 424 Hafez Ave, Tehran, Iran)
Abstract: The relationships between microhardness and microstructure, macrostructure and mechanical properties of friction stir welded joints AA6061-T913 were studied. Three equations were suggested to predict the grain size, ultimate tensile strength and yield strength from the hardness throughout the weld. Two-dimensional contour of grain size and three-dimensional maps of ultimate tensile and yield strengths were plotted according to the proposed equations. Also, the location of macroscopic zones was estimated based on hardness distribution. The modeling results were compared with the results obtained from microscopy and tensile tests. The modeling results show good agreement with the experimental findings, and the average differences between them for the ultimate tensile strength and yield strength were about 8% and 3%, respectively.
Key words: AA6061 alloy; friction stir welding; microhardness; macrostructure; microstructure; mechanical properties