Tribotesting system for hardmetal mechanical characterization

Performance of a material in a tribomechanical system can only be determined by a carefully designed simulation in which mechanical elements undergo processes similar to those in a complex engineering environment. In this paper a simple and reliable integrated testing method, in which conjoin actions involving fracture and abrasion of hardmetals together with abradant comminution, is carefully monitored and analysed. The presented system approach to tribotesting enables the mechanical characterization of hardmetals in attrition contact with granular minerals which takes place in e.g. mineral processing or in drilling action. The results from this testing show that by using one apparatus and test specimen shape it is possible to obtain a reliable rating of hardmetals according to both criteria: their fracture toughness as well as their resistance to abrasion in rubbing contact with the abradant. The integrated testing method required a theoretical or empirical model which describes the relationship between fracture toughness, other mechanical properties and the test's fracture indicator. For the range of materials tested, the best correlation received was for the empirical model for the removal of brittle material by lateral cracking.