Deposition and Characterization of Hard Coatings in the Material System V–Al–N by Reactive Magnetron Sputter Deposition

Binary and ternary hard coatings in the system V–Al–N were deposited with varying substrate bias at substrate temperatures around 350 °C by reactive d.c. and r.f. magnetron sputtering in an Ar/N2 gas mixture from a V and/or Al target. For each experiment, Si (100) and polished 1.2379 steel substrates were placed on the rotating substrate table. VN coatings were deposited at a constant Ar flow of 250 sccm, while the bias voltage was varied between −80 and −200 V. The influence of this variation on the mechanical properties hardness and reduced elastic modulus was examined by microindentation and the critical load of failure by scratch test, friction coefficient was determined by ball‐on‐disc tribometer tests. For the deposition of AlN and VAlN coatings bias voltage, Ar/N ratio and the total pressure were varied. The chemical composition of the obtained coatings was determined by electron microprobe analysis and the crystal structure of the films was characterized by X‐ray diffraction.