UNIAXIAL TENSION OF FRICTION-WELDED 304 STAINLESS STEEL AND 6061 ALUMINUM

A study of friction-welded 304 stainless steel and 6061 aluminum was conducted using uniaxial tension loading and optical two-dimensional digital image correlation (2D-DIC) to generate full field deformation maps on the surface of the specimen and to quantify the mechanical stress-strain response. A significant observation was that failure did not occur at the friction-welded interface, but instead occurred within a strain-localized neck region in the aluminum approximately 1.5 mm away from the weld interface. A detailed analysis of the 2D-DIC data set for one test specimen was used to illustrate how the mechanical response of the aluminum changed significantly from its "pre-weld" behavior due to the friction-weld process on a sub-millimeter length scale. A methodology for quantifying the mechanical property variations in the aluminum as a function of the distance from the welded interface was demonstrated using multiple, high spatial resolution, post-test "virtual extensometers".