Friction in forming proceses

This thesis deals with tests of forming operations, which are used to determine coefficient of friction. In the theoretical part of thesis, the individual tests are described in details, with the greatest emphasis on the upsetting test. In the experimental part of thesis was perform upsetting test on the cylindrical and ring samples. Coefficient of friction of the cylindrical samples was determined by a calculation method and ring samples were evaluated using diagram of calibration. The thesis includes comparison of the result received on lubricant and unlubricated samples and method for determined coefficient of friction. Graphite Delta 144 was used as a lubricant. This result show that the lubricant has a positive effect on forming process