To the Question on the Friction Assessment Methods Applied for Metal Forming Operations

Abstract

In many technological processes, friction results strong wear of the tool set and causes defect forgings. Many experimental investigations started in XX century had shown, that there are some laboratory methods with trustable results, which can be applied for friction prediction in real processes of metal forming. Among them such tests like ring compression test, direct and backward extrusion test, double cup extrusion test and T-shape compression test can be selected. Each of them has limitations that do not allow distributing the results of one certain test on all metal forming processes. Moreover, the tests should be done in a proper way to guarantee the adequate results that could be time-consuming. With the help of FE-analysis, the authors investigated numerically the intensity of the pressure distribution on the tool's surfaces and coupled the results with the real situations, observed in the metal forming operations. For the relative young T-shape compression technique oriented on the high contact pressure values authors have examined the changing of the relative deformed material volume as the merit of the friction characterisation.