Wear performance of different PVD coatings during hard wet end milling of H13 tool steel

•The tool life was improved by 100% due to the application of the AlCrN-TiAlN coating in hard end milling of H13 steel.•Tool performance is strongly correlated to the micro-mechanical properties of the coatings.•Strong loading support combined with increased impact fatigue resistance are important characteristics for coated end mills.

Wear performance of end mill tools with different PVD coatings has been studied under the condition of hard wet machining of H13 tool steel. It was shown that tool life of the coated tools could be improved by around 100% due to the application of AlCrN–TiAlN bilayer as compared to AlTiN monolayer PVD coating. Failure mechanisms of the coated tools were evaluated by SEM. The micro-mechanical characteristics of the coated tools were studied. It was shown that to achieve a better tool life under heavy loaded hard wet end milling conditions the coating should possess an improved fatigue fracture resistance combined with stronger load support shown by a higher H3/Er2 ratio. In this study we discuss the use of nanoindentation, nano-impact and micro-scratch testing to predict the wear behaviour of studied coated tools.