2015 Volume 56 Issue 10 Pages 1742-1746
Hard nanocomposite Ti–Cu–N films were deposited on high-speed-steel (HSS) substrates by pulse biased arc ion plating with a single multi-component Ti–Cu (88/12 at%) alloyed target. The effects of pulse bias duty cycle on the elemental content, structure and mechanical properties of the deposited films were investigated. The Cu atom content of the Ti–Cu–N films was analyzed using an electron probe microanalyzer (EPMA). The structure of the films was determined by X-ray diffraction (XRD) and their hardness and elastic modulus were measured using a nanoindenter. Under pulse bias voltages of −300 V and −600 V, the Cu content decreased with an increase in the duty cycle from 10% to 50%. The XPS spectra of Cu 2p for the Ti–Cu–N films showed that only pure metallic Cu was present. With an increase in the pulse duty cycle from 30% to 50%, the diffraction peaks of TiN in the preferred orientations (111) and (220) were observed, for pulse bias voltages of −300 V and −600 V, respectively. Furthermore, no obvious sign of the metallic copper phase was observed in the XRD patterns. Under both pulse bias voltages of −300 V and −600 V, the value of hardness showed first an increase and then a decrease with an increase in the duty cycle from 10% to 50%. The maximum hardness value observed was 31.5 GPa, which was obtained for a 30% duty cycle under a pulse bias voltage of −600 V.
