Development of Ultrafine-Grained Structure in 1561 Aluminium Alloy Rods during Extrusion with Shear
A structure with a mean grain size of 5-10 μm was developed in 1561 aluminium alloy during rod extrusion with shear and low reductions. It is shown that in the case of extrusion with shear through specially developed dies with backpressure and reductions of 1 < λ < 2, ductility of 1561 alloy was improved after the 1 <sup>st</sup> cycle of deformation already, while after three deformation cycles elongation in transverse direction was 24 % and 19 % in the central area of rods and in peripheral areas respectively. It was verified that extrusion pressure was decreased with each subsequent cycle. The developed tooling equipment is quite compatible with tool setup of the existing horizontal hydraulic presses.