Uniaxial and biaxial deformation characteristics of AA7075-O friction stir welded joints

摘要: The formability of friction stir welded (FSW) AA7075-O aluminum alloy sheet specimens was tested under a range warm uniaxial and biaxial loading conditions. To study the effect FSW process conditions on formability, four groups were prepared using parameters. Two rotational speeds (500 1000 rpm), travel (4.2, 5.1, 8.5, 12.7 mm/s), axial force levels (6895, 7006, 7117, 7346 N) included in test matrix. Each specimen had butt joint centrally located oriented parallel to rolling direction. Specimens from each then different combinations (e.g., transverse tensile test) (bulge test), including at two strain rates (0.0013 0.013 1/s) three temperature (25, 200, 300 °C). From flow curves obtained combination, relative that parameters (rotational speed, force) forming (temperature rate) investigated detail. Mechanical structural variations weld zone compared with those base material. Tool speed observed have major yield strength blanks, strengths varying by as much 20% over tested. Stress-strain hydraulic bulge tests yielded 5–10% increase values results. In tests, fracture only occur apex dome along line for 300 °C rate 0.0013 1/s. other did not fail this location. fractured welding either low or high rate. Otherwise, failed away line. maximum height, measure 200 °C 1/s This result correlated well stress-strain tension testing.