Effects of Al sputtering power on the structure and growth morphology of (Ti,Al)N/AlN multilayer coatings

Multilayer TiAlN and AlN coatings were deposited from two targets onto high speed steel (HSS) and hard metal (HM) substrates by pulsed DC magnetron sputtering. TiAl target power was held constant while aluminum target power was varied. Scanning electron microscopy and X-ray diffraction techniques were used for the structural and morphological characterization. Aluminum target power had an influence on the coating structure and morphology. Coatings produced with low aluminum target power had 131 type cubic structure. As the power was increased, the hexagonal structure becomes clearer.