Influence of Substrate Bias Voltage on Structure and Properties of AlCrVN Coatings Deposited by Cathodic Arc Ion Platings

AlCrN coatings cannot meet the increasing requirements for processing technology. Nano multilayer structure and multiple alloyed methods are effective method to tailor the microstructure and properties of wear resistance coatings. Metal V is easy to oxidize at high temperature to form Magnéli phase V2O5 with low melting point, which has self-lubrication effect, and reduces the friction coefficient of the coating in the wear. Here, V alloyed AlCrN coatings was deposited to study the influence of bias voltage on the properties of AlCrVN. When V is alloyed with AlCrN, the phase transition could be observed causing a congruent deterioration of the mechanical properties. When the crystal structure of AlCrVN coating remains unchanged, the wear resistance of AlCrVN coating with low V content (<7.1at.%) is better than that with high V content (>7.1at.%) while the influence of V content on the hardness of AlCrVN coating is not obvious. The properties of AlCrVN coating are also affected by its own structure which is closely related to the process of the coatings. Compared with AlCrVN coatings with high V content, the properties of AlCrVN coatings with low V content is more worthy of exploration. Therefore, the AlCrVN coatings were deposited by arc ion plating using low V content alloy target AlCrV in pure N2 and under different bias voltage. The influence of bias voltage on structure, hardness, wear was systematically analyzed, and the AlCrN coatings was prepared as a comparison. The composition, structure and morphology of the coating were characterized by X-ray diffractometer, electron energy spectrometer and field emission scanning electron microscope. The mechanical and wear properties of the coatings were tested by hardness tester, friction and wear tester and surface profilometer. AlCrVN coatings is a columnar crystal structure composed of fcc-CrN based (CrV)N substitutional solid solution phase and hexagonal Cr2N phase. With the increase of bias voltage, the content of N and Cr in AlCrVN coatings increases slightly, the content of Al decreases slightly, and the content of V does not change significantly. The crystalline phase structure and grain size of AlCrVN coatings do not change obviously, and the intensity and position of diffraction peak do not change obviously. The number of large particles on the surface of AlCrVN coatings decreases while the number of pits increases. The hardness of AlCrVN coatings increases from 22 GPa at 50 V to 24.2 GPa at 150 V, and decreases to 22 GPa at 200 V. The friction coefficient of AlCrVN coating increases from 0.42 to 0.71 for grinding Si3N4 ball at room temperature with the increase of bias voltage. The wear rate increases from 6.4×10-7 mm3/(N·m) to 13.2×10-7 mm3/(N·m), and the wear mechanism of AlCrVN coatings gradually changes from adhesion wear with a small amount of abrasive wear to abrasion wear with a small amount of adhesion wear. At low bias voltage (50 V), the friction coefficient and wear rate of AlCrVN coating are the lowest and wear resistance is the best. The friction coefficient and wear rate of AlCrVN coating with low V content (3%) are lower than those of AlCrN coating at room temperature. © 2023 Chongqing Wujiu Periodicals Press. All rights reserved.