Time-dependent rheoforging of A6061 aluminum alloy on a mechanical servo press and the effects of forming conditions on homogeneity of rheoforged samples

¹ Department of Materials Engineering, School of Engineering, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, Japan
² Institute of Industrial Science, The University of Tokyo, Meguro 4-6-1, Komaba-ku, Tokyo, Japan

^a Corresponding author: meng@sip-mi.t.u-tokyo.ac.jp

Abstract

The solid and liquid phases in semisolid metal slurry exhibited different forming behaviours during deformation result in products with inhomogeneous quality. A6061 aluminum alloy was forged in the semisolid state on a mechanical servo press with the capability of multistage compression. To improve the homogeneity of rheoforged samples a time-dependent rheoforging strategy was designed. The distributions of the microstructure and mechanical properties the samples manufactured under various experimental conditions were investigated. The A6061 samples forged in the temperature range from 625 to 628 ^∘C with a short holding time of 4 s and the upper die preheated to 300 ^∘C exhibited a homogeneous microstructure and mechanical properties. The homogeneity of rheoforged samples resulted from the controllable free motion capability of the mechanical servo press and the adjustable fluidity and viscosity of the semisolid slurry.