One of the most relevant aspects of cold forging operations is represented by the high pressures at the interface between the tools and the workpiece and the high temperature peaks due to material adiabatic heating. Consequently, friction plays a fundamental role for the competitiveness of the process and it is essential that the lubricants withstand the interface conditions encountered in the different forging stages in order to form quality parts.
The objective of the research work is to investigate the friction behaviour of new environmental-friendly solid lubricants under process conditions, with particular attention to the dies temperature parameter.
The case study refers to the impact extrusion of the AA1050 alloy. Experimental values of the friction coefficient are determined through laboratory tests and numerical simulation, reproducing controlled variation of the surface expansion and the tool temperature in the range 20-150°C.