Feasibility of metal forming in semi-liquid state

The work described in this paper is connected with Authors' earlier research on the formability of alloys in semi-liquid (partly liquid) state, i.e. at the temperatures exceeding their solidus points. Two aluminium based alloys of a relatively large crystallization temperature range have been used as the testing materials. The investigation focused on the effect of the liquid fraction (volume percentage of liquid component in the alloy, pre-heated to the temperature above its solidus point) on the parameters of the plastic deformation. The process of upsetting of the cylindrical specimens is investigated. The prime objective of the work is to determine the factors which affect the softening of various alloys subjected to deformation in semi-liquid state. An attempt of the generalization of the problem is done. Thermal-mechanical finite element model developed for the compression process and adapted to the semi-liquid conditions is used for the calculation of the deformation parameters.