Mechanism of adaptability for the nano-structured TiAlCrSiYN-based hard physical vapor deposition coatings under extreme frictional conditions

摘要: Recently, a family of hard mono- and multilayer TiAlCrSiYN-based coatings have been introduced that exhibit adaptive behavior under extreme tribological conditions (in particular during dry ultrahigh speed machining hardened tool steels). The major feature these is the formation tribo-films on friction surface which possess high protective ability operating temperatures 1000 °C above. These are generated as result self-organization process friction. But mechanism how films affect adaptability coating still an open question. proposed in this paper associated with strong gradient within layer nano-scaled tribo-films. This trend was outlined by performed thermodynamic analysis phenomena combined developing numerical model heat transfer cutting zone based finite element method. results theoretical studies show physical-chemical processes mostly concentrated nano-tribological phenomenon produces beneficial distribution at chip/tool interface controls life wear behavior.Results x-ray photoelectron spectroscopy indicate enhanced sapphire- mullite-like TiAlCrSiYN/TiAlCrN coating. Comprehensive investigations structure phase transformation operation performed, using resolution transmission electron microscopy, synchrotron radiation technique: absorption near-edge XRD methods.The data obtained efficiently perform their thermal barrier functions preventing to penetrate into body coated tool. Due damaging well non-beneficial (formation AlN hex phase) drastically diminishes Micro-mechanical properties measurements room elevated hardness appears stable 500 °C then drops little 600 °C but remains high. It means if can reduce actual temperature down level underneath able withstand heavy loads operation.