Comparative studies on mechanical properties and cutting performance of Cr-Al-Si-N coated micro tool for high speed machining applications were performed. Quaternary Cr-Al-Si-N coatings, in which Si was incorporated into Cr-Al-N, were synthesized onto WC-Co substrates using a hybrid system of an arc ion plating (AIP) and DC magnetron sputtering techniques. The high hardness of Cr-Al-Si-N coatings was related to the composite microstructure consisting of fine CrN crystallites and amorphous Si3N4. The hardness values of the Cr-Al-Si-N (~55 GPa) coatings were significantly increased compared with those of Cr-Al-N (~24 GPa) coatings. Cutting tests were carried out to evaluate the performances of micro endmill coated tool in high-speed cutting conditions. Consequently, the quaternary Cr-Al-Si (8.7 at.%)-N coated micro end-mill under dry machining showed good cutting performance in micro end-milling process of AISI D2 work material (HRC 24).

Keywords: Hybrid coatings, Cr–Al-Si–N nanocomposite, Microstructure, Microhardness, Tool wear