**2. Methodology and experimental details**

The deposition of the coatings was performed using a multi-target sputtering magnetron. This specific type of system allows to perform the multilayer deposition process in situ. This equipment uses four (4) magnetrons (Torus - 4 ", 10 cm Kurt J. Lesker) with diameters of 10 cm, three (3) radio frequency sources (13.56 MHz, RFX 600A), and three (3) direct current sources (MDX 500, Advanced Energy). In addition, the pressure during the deposition process in monitored by a control and measurement system (Baraton, MKS), which has four (4) gas flow controllers, a radiation heating system (Athena 500), which has a maximum temperature of 400°C, and a planetary type rotary sampling system. For TiN, TiCrN, TiCN, BCN and CrAlN coatings, titanium (Ti), titanium carbide (TiC) and Chromium-Aluminum (Cr-Al) targets were used, respectively; each cathode with an approximate purity of 99.99%. Two (2) different type of substrate were used, silicon with preferential crystallographic orientation (100) and AISI 1045 and H13 steel substrates respectively. The silicon substrates were subjected to a surface cleaning process in an ultrasonic system and the steel substrates were prepared superficially using sandpaper (SiC) and finally polished in a metallographic polisher. Before starting the deposition process, a vacuum with a pressure of 1.4x10−4 mbar was applied. The TiCN coating was deposited using a working pressure of 1.4x10−2 mbar in a gas mixture of 50 sccm (Ar) and 16 sccm (N2) at 250°C, and a r.f power density of 5 W/cm<sup>2</sup> was applied on the TiC target. For BCN coating, it was deposited by a pressure of 7.4x10−3 mbar in a gas mixture of 44 sccm (Ar) and 6 sccm (N2) at 250°C, and a r.f power density of 7 W/cm<sup>2</sup> was applied on the BC target. For the CrAlN coating was deposited using a working pressure of 6.4x10−3 mbar was used a gas mixture of 50 sccm (Ar) and 5.5 sccm (N2) at 250°C, and the r.f power density applied to the Cr target and Al target was 2.5 W/cm<sup>2</sup> and 4.5 W/cm2, respectively [8]. The deposition of the Si3N4 based coatings was performed by magnetron sputtering with an r.f source (13.56 MHz) on silicon (100) and AISI 316 stainless steel substrates. A cathode (Si3N4) with a purity of 99.9% approximately. During the deposition a power of 550 W was used and a bias voltage of −20 V was applied, the distance between substrates-targets was approximately 7 cm, and the deposition process was carried out at a temperature of 200°C inside the chamber. In addition, the substrate holder rotated at a

#### *Analysis of the Tribological Evolution of Nitride-Based Coatings DOI: http://dx.doi.org/10.5772/intechopen.100629*

speed of 60 RPM during the entire deposition process with a working pressure of 5.1x103 mbar. The coating obtained a thickness of approximately 2.5 μm.

The structural analysis of TiCN, BCN and CrAlN coatings was analyzed by X-ray diffraction (PANalytical X 'pert proTM), using a Cu Kα radiation source with a wavelength of λ = 1.5405 Å. By X-ray photo-electron spectroscopy (XPS) using a SAGE HR100 (SPECSTM) equipment with a monochromatic source (Mg Kα 1253.6 eV), CasaXPS V2.3.15 software was used to determine the chemical composition of the obtained coatings. The morphological study of the coatings was carried out by atomic force microscopy (AFM) with an Asylum Research MFP-3D® device and with a scanning prove image processor (SPIP®), the grain size and roughness of the coatings obtained were calculated. The mechanical study was carried out by nanoindentation using an Ubi1-HysitronTM device, which uses a Berkovich diamond tip at variable loads. From this test, load–displacement curves were obtained as a function of penetration for the coatings. Based on these curves, hardness and elastic modulus were determined using the Oliver-Phar method.
