Characterization of pre-and/or post-treated PVD-AlTiN coating: Nanohardness, modulus of indentation and percent elastic portion of the nanoindentation

Abstract It has been widely reported that cutting tools showed improved mechanical properties and better machining performance with different pre-and post-treatments. The performance of hard thin coatings can be optimized by knowing the effect of surface pre-and post-treatments on the coating properties. Hard thin coatings are characterized by their hardness, effective young’s modulus, and elastic recovery. This study aimed to evaluate the effect of the microblasting and/or cryogenic treatment as a pre-and/or post-surface treatments on the nanohardness, modulus of indentation, and percent elastic portion of the nanoindentation of single layer PVD-AlTiN coating deposited on the tungsten carbide insert. The characteristics of hard thin coatings have been determined from loading/unloading curves measured by a computer controlled Fischerscope PICODENTOR HM500 nanohardness tester and a maximum depth of the diamond indenter impression into the coating at a given load of 30 mN for 20 s. It has been observed that the value of the indentation depth and the area between the loading/unloading curve decreases with an increase in the nanohardness and modulus of indentation (effective Young’s modulus) of the thin hard coating. It has been observed that the coated-microblasted as a post-treatment produced higher nanohardness (2833.6H.V.) and better resistance to plastic deformation (0.08 GPa) as compared to other pre-and/or post-treatments considered in the present study.