Rotations of brittle particles during plastic deformation of ductile alloys

Experimental evidence is presented to show that significant rotations of brittle phase inclusions of a Fe-rich intermetallic phase occur during plastic deformation on an AlMgSi base wrought aluminum alloy. The particle rotations are quantitatively characterized, for uniaxial tension, compression, torsion, and notch-tension test specimens strained to different strain levels. The particle rotations are monitored by measuring the morphological orientation distribution function of the particles. Significant particle rotations occur under all loading conditions. The morphological orientation distribution function evolves with plastic strain under uniaxial tension, compression, and torsion. The particles tend to align themselves in the direction parallel to applied (or induced) tensile stress for deformation under tension and compression. In the case, of torsion test specimens, at least up to 98% torsion strain, the particles tend to align along the direction at an angle of 45° to torsion axis.