Influence of dry micro-blasting grain quality on wear behaviour of TiAlN coated tools

► Micro-blasting on PVD coated tools increases film hardness and brittleness. ► Simultaneously, the substrate at the cutting wedge may be revealed. ► For enhancing cutting performance, micro-blasting pressure and time have to be optimized. ► Hereupon, the applied grain properties and kinematics have to be also considered. The effects of Al 2O 3 and ZrO 2 grains, in dry micro-blasting of coated cemented carbide inserts, on film's hardness and brittleness, cutting edge geometry as well as on tool life are introduced. Nanoindentations on film surfaces, at various pressures micro-blasted, revealed the influence of the different micro-blasting grains on the coating superficial hardness. For investigating the effect of the developed film compressive stresses at certain micro-blasting pressures and grain qualities on the film's brittleness, nano-impact tests were conducted. Moreover, roughness and cutting edge geometry measurements were carried out via confocal microscopy and EDX microanalyses after micro-blasting by Al 2O 3 or ZrO 2 grains for detecting potential film thickness decrease and substrate revelation. The wear behaviour of coated and variously micro-blasted tools was investigated in milling of hardened steel. The attained results provide insight concerning optimum selection of micro-blasting data in various grain cases, for improving the cutting performance of coated tools.