Influence of Substrate Bias Voltage on Structure, Morphology and Mechanical Properties of AlCrN Coatings Synthesized Using Cathodic Arc Evaporation

Abstract

AlCrN is one of the most widely studied hard coatings, especially if it is about their thermal resistance and mechanical properties. However, adhesion and wear resistance of AlCrN coatings synthesized from an cathode has not been studied yet. The influence of substrate bias voltage on the properties of coatings formed by cathodic arc evaporation was investigated. The morphology, phase and chemical composition, hardness, adhesion as well as wear of the coatings were analyzed by XRD, EDX, SEM, nanoindenter, scratch and ball-on-disc testers. It was found that as the negative substrate bias voltage (UB) increased, the rate of deposition and the macroparticle number on the surface of the coating decreased, mainly due to the resputtering phenomenon. X-ray diffraction showed that the intensity of h-AlN diffraction lines decreases and the intensity of the cubic CrN diffraction lines increases with the increase of the negative substrate bias voltage. The hardness of the coatings increases and crit ical load Lc2 decreases with negative substrate bias voltage. The lowest wear rate, about 1.1×10 -16 m 3 /Nm, was observed for coating deposited at bias of -100 V.

The effect of substrate bias voltage on the mechanical and electrochemical corrosion properties of multilayered CrN/CrAlN coatings produced by cathodic arc evaporation

“…MPs are a typical defect in the CAE process that influences the surface roughness, mechanical properties, and electrochemical corrosion behavior of the deposited film. Accumulating evaporated metal on the cathode, which leads to liquid droplet formation, is the main origin of MPs in the CAE process 36,37 . The number of MPs decreases by increasing the bias voltage, which is consistent with the results reported by Huang et al 38 …”

Quo Vadis: AlCr-Based Coatings in Industrial Applications

“…Dual-phase coatings with Al concentrations of more than 70 at.% have been reported as monolayer coatings [88,90,94,95], as well as multilayers [66,96]. The coatings are characterised by relatively low hardness compared with fcc (Al,Cr)N, lower oxidation resistance than fcc (Al,Cr)N with a high Al content, but also with the positive effect of exhibiting lower stress.…”

The Effect of Al and Ti Transition Metals on the Wear Resistance of Ceramic Based CrN Coatings; Investigation under Ambient Air and Vacuum Conditions

“…Trace amounts of oxygen was encountered in all coatings as an unintentional influence of the cathodic arc evaporation method. 20 The section thicknesses of the coatings and their structure images in the cross-section are given in Figure 3. In CrN coating (Figure 3(a)), it was seen that the grains grow preferably lying perpendicular to the surface, likewise had a dense and columnar like cauliflower texture structure.…”

“…19 In another study, the great properties of AlCrN at elevated temperatures were attributed to the amount of Al and the phase transformation. 20 When the Al content is less than 75%, the c-AlN regular phase is formed. 21 The increase in Al content supports the formation of the h-AlN phase, and leading to a decrease in hardness and mechanical properties.…”

“…22 In coating applications, the microstructure and layer thickness, which vary depending on the deposition conditions, and the type of substrate together with these, effect on the coating performance. 20,23 Ambiger et al produced AlCrN coatings in different layer thicknesses by using two different substrates, namely low carbon (EN353) and high carbon (EN31) steels, by controlling the coating parameters. 24 As a result of tribological tests, it was reported that a thicker layer coated on high carbon steel showed better wear performance than others.…”