**Abstract**

The chapter presents an analysis of selected magnesium alloys as structural materials to be used in production of parts as well as their technological parameters in some manufacturing processes: metal forming and joining. Taking into account the analysis of microstructure and mechanical properties of conventional and new magnesium alloys and requirements of their possible applications (aviation, automotive, sport, etc.), the study of forming parts/products based on description of plastic formability of magnesium alloys in the processes of bulk metal forming (forging, extrusion, KOBO extrusion, rolling) and joining (friction stir welding) has been presented. Upsetting test, backward extrusion, and KOBO extrusion of complex cross-sectional profiles and forging process were conducted using magnesium alloys such as AZ31, AZ61, AZ80, WE 43, and Mg alloy with Li for the production of thin-walled profiles and forged parts. The range of temperatures and extrusion rate for manufacturing of these profiles were determined. Tests also covered the analysis of microstructure of Mg alloys in the initial state as well as after the extrusion process. The recommendations for realization of metal forming and joining processes of selected magnesium alloys have been presented.

**Keywords:** magnesium alloys, plastic formability, forging, extrusion, KOBO extrusion, rolling, joining, friction stir welding
