Lubricant failure in sheet metal forming processes

The application of tribology to sheet metal forming processes (SMF) contributes to a general industrial aim i.e., to make products of high quality at an increasingly competitive way, by enhancing the tool life and maintaining a constant level of friction during forming. Both aspects are served by the development of models, able to predict friction and wear. This thesis provides such a model, restricted to lubricated SMF-operations and focused on prediction and control of galling (initiation). The main hypothesis of the work - galling initiation in lubricated sheet metal forming processes occurs at the asperity level as a result of the fact that the lubricant’s critical temperature is exceeded, due to frictional heating -, is validated by a combination of modelling, experimental work and industrial trials.