Characterization of TiAlCrYN nanocomposite coatings prepared using four-cathode reactive unbalanced direct current magnetron sputtering system

In this study, approximately 1.5–2.5 μm thick, TiAlCrYN nanocomposite coatings were deposited on various substrates such as high speed steel (HSS) drill bits, mild steel and silicon by reactive magnetron sputtering. The coatings were characterized using X-ray photoelectron spectroscopy, X-ray diffraction, field-emission scanning electron microscopy and nanoindentation techniques. TiAlCrYN nanocomposite coating exhibited hardness of the order of 25 GPa. Micro-Raman spectroscopy was used to characterize the structural changes as a result of heating of the TiAlCrYN nanocomposite coatings in air (600-1000oC) and the coatings were found to be thermally stable in air up to 900oC. For the performance evaluation, the TiAlCrYN coated high-speed steel (HSS) drill bits and uncoated HSS drill bits were subjected to accelerated machining conditions. The uncoated HSS drill bits failed after drilling 50 holes, while drilling a 12 mm thick 304 stainless steel plate, whereas, the TiAlCrYN coated drill bits averaged 657 holes before failure