Process Window Determination for Thixoextrusion Processes Using a Steel Alloy
A direct semi-solid bar extrusion process is characterised by inserting a feed stock in a container and extruding through a forming die with a punch. Compared to conventional bar extrusion the use of semi-solid material complicates the process due to the requirement of solidification of the material. To achieve the solidification of the semi-solid bar, different basic tool concepts are presented. With a combination of these concepts experiments were carried out using the steel alloy X210CrW12 to detect the influence of the most influencing parameters press velocity, extrusion channel diameter, length and geometry. Numerical simulations enable a better understanding of the process mechanics like temperature development in the billet and forming die as well as the material flow in the deformation zone.
G. Hirt, A. Rassili, A. Bührig-Polaczek
F. Knauf et al., "Process Window Determination for Thixoextrusion Processes Using a Steel Alloy", Solid State Phenomena, Vols. 141-143, pp. 61-66, 2008