Oxidation Resistance of CrAlN Films with Different Microstructures Prepared by Pulsed DC Balanced Magnetron Sputtering System

Abstract

CrAlN films were prepared using a pulsed DC balanced reactive sputtering system under different N 2 /Ar ratios and pulse widths. We investigated the oxidation resistance of two CrAlN films with different microstructures; i) with a fcc-CrN structure, lower internal stress and moderate hardness, and ii) with a mixed structure of hcp-AlN and hcp-Cr 2 N phases, higher internal stress and super high hardness of 41 GPa. The CrAlN film (i) having the single fcc-CrN structure showed good oxidation resistance up to 900 C. The plastic hardness of this film increased to a maximum of 38.5 GPa at 900 C. In contrast, the CrAlN film (ii) with the mixed structure of hcp-AlN and hcp-Cr 2 N phases was stable up to 800 C. The plastic hardness of this film decreased gradually with annealing.

Influence of total gas pressure on the microstructure and properties of CrAlN films deposited by a pulsed DC balanced magnetron sputtering system

“…However, little is currently known about the role of the partial pressure of reactant gas on the microstructure of the films prepared in pulsed DC magnetron sputtering systems. CrAlN films are well known for their outstanding properties such as high toughness, high compressive residual stress, excellent film adhesion, low surface energy and high wear resistance [12][13][14][15][16][17][18][19][20]. Over recent years a general approach aimed at improving the properties of CrAlN film has been to increase its Al content to improve its structure and increase its thermal stability.…”

Quo Vadis: AlCr-Based Coatings in Industrial Applications

“…Oxidation then starts already at 800 • C. These coatings already have an hcp structure. The negative influence of the hcp structure on the oxidation resistance was confirmed by [79].…”

Influence of Pvd Deposition Mode on the Quality and Integrity of CrAlN Thin Films: A Study of Magnetron Sputtering Processes on Stationary and Rotating Substrates

“…The crystallite size was determined using Scherrer's formulas [30]. Analytical modeling based on Stoney's equations [13] provided a realistic evaluation of residual stresses, while nanoindentation techniques were utilized [31][32][33] to identify the hardness and stiffness of the CrAlN layers. This enabled the consideration of the substrate effect on the nanoindentation results to extract the true hardness and stiffness properties of the CrAlN coating layers.…”