Influence of Deformation Process Parameters on Changes in Microstructure and Properties of Mg-8Li-2Ca Alloy

Currently, the aviation and automotive industries are seeing increasing interest in magnesium alloys. The manufacture of semi-finished and finished magnesium alloy products is mainly based on casting technology, which results from the good casting properties of these materials. There are some difficulties using plastic processing for magnesium alloys but it offers better mechanical properties. For these reasons, alternative ways of plastic forming are being sought for magnesium alloys. Research has also been undertaken into the development of production and forming technology of a new group of ultralight Mg-Li-Ca magnesium alloys, using conventional (classical extrusion) and unconventional plastic forming methods (KoBo extrusion). The paper presents the results of the study on plastic forming of Mg-8Li-2Ca alloy. The research material consisted of ingots with the dimensions ϕ 40 x 90 mm. Before the deformation process, the ingots were subjected to heat treatment. Classical extrusion tests and extrusion by SPD methods (KoBo) were performed. Using light and electron microscopy, the changes formed in the microstructure of the Mg-8Li-2Ca alloy in the initial state and after plastic deformation processes (classical extrusion, KoBo extrusion) are presented. Quantitative analysis of the microstructure of the Mg-8Li-2Ca alloy was performed using Metilo software after the deformation process. The mechanical properties were evaluated based on the results from the conducted HV0.2 hardness measurements and the static tensile test performed at room temperature.