INFLUENCE OF FRICTION COEFFICIENT ON MECHANICAL PROPERTIES IN PROCESS OF COLD BULK FORMING
- 1 University of Maribor; Faculty of Mechanical Engineering, Maribor, Slovenia
Bulk forming is one of the most effective and efficient manufacturing processes. Mass production of many of the items without any defects has been possible because of the advancements in cold bulk forming. The characteristic of a lubricant, especially coefficient of friction influences the interfacial friction during the forming process. This friction causes defects and many difficulties and has to be kept within limits so the proper choice of lubrication is very important for the quality of the formed product. The influence of lubricant’s coefficient of friction on different mechanical and electrical properties of cold extruded material has been investigated and described in this paper by performing many different tests and measurements for mechanical properties and electrical conductivity of the formed material. Coefficients of friction for four different lubricants were first obtained by ring test, and then these lubricants were used in cold extrusion process. The obtained experimental results describing the effect of lubrication on material properties were presented in a form of diagrams and have shown that choice of lubrication could influence some material properties.