Structure, hardness, and tribological properties of reactive magnetron sputtered chromium nitride films

Abstract

Chromium nitride (CrN) films with Cr/N atomic ratios of 0.73–1.46 were prepared by reactive dc- magnetron sputtering with Ar as the sputtering gas and N2 as the reactive gas. The application of a negative bias voltage to the substrates and the decrement of the gas flow ratio of N2 to Ar (or FN2/FAr) promoted the growth of CrN films with preferred orientations of (200)+(220), high Cr/N ratios, and high densities. The functional hardness and compressive stress were highly dependent on the magnitude of the bias voltage and the Cr/N ratio that was adjusted by the FN2/FAr ratio during film deposition. The optimal energy conditions for ion impingement on growing CrN films with compact columnar crystal structure, high hardness, and enhanced tribological properties were studied with respect to the modulations of the bias voltages and the Cr/N ratios. The CrN films with high hardness and high wear resistance were synthesized in this study at low bias voltages of −(100–300) V and FN2/FAr ratios of 1–3.

The effects of substrate bias, substrate temperature, and pulse frequency on the microstructures of chromium nitride coatings deposited by pulsed direct current reactive magnetron sputtering

“…The texture of thin films developed by PVD process has been discussed extensively. 2,3 Film texture can be influenced by deposition methods and processing variables, energetic ion bombardment, nature of the substrate, and geometrical confinement by surface features. 1 The poisoning of metal targets is common during the reactive direct current (DC) sputtering process of thin films.…”

Surface chemical changes induced by low‐energy ion bombardment in chromium nitride layers

“…Implications of the effect of ion bombardment on the composition and structure of the CrN films have been clearly demonstrated recently. 6 This oriented our attention towards investigations of the effect of Ar C and N 2 C bombardment on the CrN x layers of different composition and structure. Conclusions were made upon possible alterations of the Cr 2 N and CrN stoichiometry by these bombarding ions.…”

Structural and mechanical characterisation of the chromium nitride hard coating deposited on the silicon and glass substrate

“…To deposit the hard coating, sputtering is normally used from the available processes because of its high deposition rate, thin compound nature with controlled stoichiometry, simplicity and cost-effectiveness compared to the radio frequency (RF) system. Among the various techniques available for the deposition of CrN thin films, reactive magnetron sputtering could be effectively used to tailor the micro structural features of the films [9][10][11][12][13][14][15][16][17]. For some years, chromium nitride coatings have been gaining popularity and becoming important technological materials in the fields of cutting and forming tools, bearing and machine parts, dies and moulds.…”