STUDIES ON THE CONDITIONS OF HOMOGENIZATION AND PROPERTIES IN HOT FORMING OF ZK60 CAST MAGNESIUM ALLOY

This paper presents a study of temperature conditions for the homogenization of a cast high-strength ZK60 alloy belonging to the Mg-Zn-Zr group of magnesium alloys. On the basis of a literature review, two-stage homogenization conditions were selected to improve the forgeability of the ZK60 casting. The effectiveness of this treatment was evaluated experimentally on the basis of structure and hardness tests and was found to be satisfactory. Plastometric tests were carried out for the samples made from the ingots after homogenization. These tests were performed in a compression test in hot forming conditions at three temperatures (350 0C, 400 0C and 450 0C) and four strain rates (0,01; 0,1; 1,0 and 10 s-1). The determined flow curves will be used to develop a material model of the cast magnesium alloy ZK60 for numerical simulations.