KOBO Extrusion Machine

An economical and efficient method of deformation, which creates a chance to obtain a stable and fragmented microstructure of the product, is the cold extrusion of metal through a die twisted on both sides, the so-called KOBO method. The method was developed at the AGH University of Science and Technology as a structural criterion for designing plastic processing processes of metallic materials. It consists of taking complete control of the evolution of the substructure and the related mechanical properties of the deformed metal through external interference in the manner of its plastic flow. In particular, being the essence of the KOBO method, properly induced periodic changes in the deformation path lead to a several-fold reduction of the plastic resistance, which in practice means not only a significant reduction of the process energy, but above all obtaining the desired, fine-grained and homogeneous structure, and thus high functional properties.

The stand consists of a horizontal hydraulic press (Hydromet, Bytom, Poland) with a punch force of 100 T equipped with a module that allows for double-sided (reverse) rotation of the die, a recipient and a cooled die holder.

Location: AGH – University of Science and Technology, Faculty of Non-Ferrous Metals, Department of Materials Science and Engineering of Non-Ferrous Metals

References:
P. Długosz, W. Bochniak, P. Ostachowski, R. Molak, M. Duarte Guigou, M. Hebda, The Influence of Conventional or KOBO Extrusion Process on the Properties of AZ91 (MgAl9Zn1) Alloy, Materials (Basel). 14 (2021) 6543. doi:10.3390/ma14216543.