Frictional behaviour of environmentally friendly lubricants for sheet metal forming processes

In last decades, national legislations have become even more restrictive with respect to the application and the disposal of hazardous lubricants in sheet metal forming. The introduction and the continuous improvement of environmental friendly solutions has seen a continuous growth and attention, but today the usage of traditional hazardous lubricants is still significant, requiring expensive cleaning operations and harmful cleaning agents to remove them. The use of solid organic lubricants can reduce or eliminate this drawback, despite their performances may be significantly affected by specific process parameters and the presence of debris. In this paper the performances of a solid organic lubricant have been compared to traditional liquid lubricants applied to sheet metal forming applications. Different surface topographies have been reproduced and the effects in terms of frictional behaviour have been investigated.