Surface chemistry of PVD (Cr,Al)N coatings deposited by means of direct current and high power pulsed magnetron sputtering

Abstract

(Cr,Al)N protective coatings were deposited using direct current (DC) and high power pulse magnetron sputtering (HPPMS) technology. The chemical analysis of the surface near region of the coatings was performed by means of X‐ray photoelectron spectroscopy (XPS) and was correlated to the deposition parameters and resulting coating morphology. A surface oxidation process was observed by means of angle resolved XPS studies and XPS sputter profiles. Both DC and HPPMS coatings showed a non‐stoichiometric chemical composition with a significant excess of cations (chromium and aluminum) in the bulk structure, leading to a metastable phase. The passivation reaction of the surface near region leads to an anion to metal ratio which goes along with an enrichment of aluminum in the surface near region as a thermodynamically favored composition in equilibrium with the ambient atmosphere. Interestingly, the variation of the pulse duration of the HPPMS process, which led to a change of the peak current, had a strong influence on the resulting composition of the surface near region. Copyright © 2013 John Wiley & Sons, Ltd.

Tailoring CrNx stoichiometry and functionality by means of reactive HiPIMS

“…Other examples of applications of metal nitrides are diffusion barrier layers, infrared or decorative coatings, where the precise control of stoichiometry results primordial to tailor their practical performance. Particularly, Cr(Al)N films have been perhaps one of the most studied systems due to their high hardness, corrosion-resistant and anti-wear properties, with a high demand in many industrial applications like molding, forging, machining and plastic processing [6,[16][17][18][19][20][21][22][23][24]. Many established PVD methods have been employed for the preparation of these hard transition metal nitride coatings, like vacuum-arc [25], pulsed laser deposition [26], DC-magnetron sputtering [12,17,18], pulsed-DC (10-350 kHz) [27], and more recently, HiPIMS and modulated pulsed power-MPP (<1 kHz) [5,6,16,[28][29][30].…”

Structure, corrosion, and tribological properties of CrSiN coatings with various Si contents in 3.5% NaCl solution

“…A lot of mechanical parts such as piston pumps, gear, shaft, and propeller working in ocean conditions face severe damage, which leads to urgent needs for protective and lubricating coatings . CrN coatings have been widely used as a protective material in industrial areas due to its high hardness, superior thermal conductivity, good chemical stability, outstanding wear resistance, and excellent anti‐corrosive properties . Nevertheless, CrN coating can't get enough requirement in some extreme conditions because of its high friction coefficient .…”

“…[1][2][3] CrN coatings have been widely used as a protective material in industrial areas due to its high hardness, superior thermal conductivity, good chemical stability, outstanding wear resistance, and excellent anti-corrosive properties. [4][5][6] Nevertheless, CrN coating can't get enough requirement in some extreme conditions because of its high friction coefficient. [7][8][9][10][11] The addition of third element such as silicon into CrN binary compound can significantly enhance the mechanical and tribological performances.…”

Insight into Al existing form and its role on microstructure and properties of Cr1−xAlxN films

“…It can be seen from Fig. (a) that the Cr 2p spectrum is composed of two peaks centered at 575.4 and 585.4 eV, corresponding to Cr 2p 3/2 and Cr 2p 1/2 , respectively. The N 1s spectrum [see Fig.…”