Wear resistance of a coated hard-alloy tool in the machining of high-temperature chromium alloys

Resumo

The influence of the hard-alloy substrate and the composite coatings of a tool on its wear resistance in the machining of high-temperature chromium alloys is investigated. The effectiveness of the coated hardalloy tool is determined by the properties of the hard alloy and the coatings. For hard alloys characterized by relatively low strength and crack resistance, the coatings prove ineffective, on account of the brittle failure of the substrate and the consequent destruction of the coating. On alloys with low thermal stability, the coatings are ineffective on account of weakening of the binder at the high temperatures associated with machining. It makes sense to use a hard alloy with mechanical properties such that the coating may operate effectively. Better properties are not needed.