Selection of high pressure torsion processing modes for fabrication of Al-Mg metal matrix composites Available to Purchase

A hybrid composite material fabricated from Al-Mg system using high-pressure torsion (HPT) with 10, 20 and 30 anvil rotations was studied in the present work. Fabrication of three-layer Al-Mg-Al and Mg-Al-Mg composites was performed at room temperature on Bridgman anvils in constrained mode under a pressure of 5 GPa and N=10, 20 and 30 revolutions, at a rotation speed of ω=2 rpm. In case of Mg-Al-Mg system bulk composite structure was not formed during HPT. The obtained monolithic samples had a layered structure. In case of Al-Mg-Al disc set, monolithic composite samples were formed after N=10 and 20 anvil rotations. Increase of rotations number to N=30 results in the loss of bulk structure due to an emergence of cracks in areas between the layers. The most intensive fragmentation and mechanical alloying of Mg in Al were observed after HPT with N=20 revolutions. Three zones with different microstructure types were observed after HPT: the central zone where mixing of the components did not occur, the mid-radius zone with vortice-type foldings, and peripheral zone with a homogeneous distribution of magnesium in the aluminium matrix. The microhardness measured along the diameter of the obtained composite materials changed nonmonotonically. Obtained results contribute to fundamental understanding of processes taking place during mechanical alloying induced by HPT.