Influence of different tool materials, coatings and lubrications onto shape accuracy during micro impact extrusion

In this paper the impact of different tool materials, tool coatings, and lubricants onto the micro forming process of micro cavities is investigated. As tool materials two different hardened steels were used for the forming die. To lower the friction and adhesion between forming tool and aluminium substrate three coatings TiN (titanium nitride), TiCN (titanium carbon nitride), and DLC (diamond like carbon) were tested. Furthermore, the influences of different lubricants were studied. Geometric parameters and surface quality were judged by laser microscopy and SEM images of metallographic sections.