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Utilizing reactive DC magnetron sputtering method, TiN coatings were deposited on the silicon substrates at different nitrogen flows and powers. A study of the X-ray phase composition of the coatings was carried out. The stoichiometric composition of the coatings was determined using energy dispersive x-ray spectroscopy. The structure of the surface, cross-section, and thickness of the coatings were determined using scanning electron (SEM) and atomic force microscopy (AFM). A significant change in the surface structure of TiN coatings was established with changes in deposition power and nitrogen flow. SEM images of cross-sections of all coated samples showed that the formation of coatings occurs in the form of a columnar structure with a perpendicular orientation relative to the silicon substrate. The mechanical properties (elastic modulus E and microhardness H) of TiN coatings of the first group demonstrate a maximum at a nitrogen flow of 3 sccm and are 184 ± 11 GPa and 15.7 ± 1.3 GPa, respectively. In the second group, the values of E and H increase due to a decrease in the size of the structural elements of the coating (grains and crystallites). In the third group, E and H decrease. Microtribological tests were carried out in 4 stages: at a constant load, multi-cycle for 10 and 100 cycles, and with increasing load. The coefficient of friction (CoF) and specific volumetric wear ω depend on the roughness, topology, and mechanical properties of the resulting coatings. Fracture toughness was determined using nanoscratch and depends on the mechanical properties of TiN coatings. Within each group, coatings with the best mechanical and microtribological properties were described: in the first group—TiN coating at 3 sccm (with (29.6 ± 0.1) at.% N), in the second group—TiN coating at 2 sccm (with (40.8 ± 0.2) at.% N), and in the third group—TiN coating at 1 sccm (c (37.3 ± 0.2) at.% N). [ABSTRACT FROM AUTHOR]

Diamond-Like Carbon (DLC) coatings have high wear resistance, hardness, biocompatibility and chemical inertness. Secondary structures, which formed at the track in dry friction conditions, provide friction reduction. Doping DLC with both metallic and non-metallic elements leads to a rearrangement of the structure of graphite clusters, a change in their properties, and facilitates the formation of secondary structures. In the present, the silicon atoms were used to create the compositional structure of DLC surface layers at the level of the crystal lattice. DLC-Si coatings with the thickness of 2 µm were deposited on a (Cr, Al, Si)N layer with the thickness of 3 µm formed on a steel substrate. DLC-Si layer was deposited by plasma-enhanced chemical vapor deposition using acetylene and tetramethylsilane. Nanoindentation in the wear mode was used to study the nanomechanical properties of the surface. Atomic force microscopy was used to visualize the surface morphology and wear traces. In this study, secondary structures were created in a microfriction process using a NanoScratch mode. The surface structures after microfriction was observed by atomic force microscopy, and the specific surface energy was measured. The specific volumetric wear rate of the coatings after microfriction was estimated. During microtribological testing with double squares the specific volumetric wear rate of DLC coatings was 5.39·10-14 m3/N·m for 0.8 % Si and 12.39·10-14 m3/N·m for 10 % Si. When tested in the form of scratches, the specific volumetric wear rate for the coating was for the DLC-0.8 % Si (1.22 – 10.71)·10-14 m3/N·m and for the DLC-10 % (6.17 – 49.55) ·10-14 m3/N·m. [ABSTRACT FROM AUTHOR]

[Display omitted] • DLC-Si coatings were deposited on the steel substrate using cathodic arc evaporation. • The nanostructure of the DLC-Si surface is managed by the Si(CH 3) 4 flow rate. • I D /I G ratio correlates with the properties of the DLC-Si coatings. • E and H maps of the DLC-Si coating surface were obtained by nanoindentation. • The nanoscale structure of the secondary layers is shown by AFM for the first time. DLC-Si coatings obtained by cathodic arc evaporation on the (CrAlSi)N sublayer were investigated. The effect of Si addition to DLC on the I D / I G ratio, surface morphology, elastic modulus of surface layers, distribution of elastic modulus and microhardness (over the surface and depth of the coating), specific surface energy, coefficient of friction, wear, and thickness of nanoscale layers formed during friction was studied. The nanoscale thickness of the secondary structures has been evaluated by atomic force microscopy for the first time. It has been established that secondary structures are assembled into nanosized layers and chains, which is explained by sp 2 bonds between nanosized clusters. The most hardened layer after friction is formed on the DLC + 0.8 % Si coating. The maps of the elasticity modulus and microhardness distributions are presented. The significant contact pressure is the driving force causing the transformation of the DLC phases during friction. According to the results of microtribotests in wear tracks after macrotests, the average values of the coefficient of friction from microtests correlate with the thickness of the secondary structures on the silicon content of the coatings and with the specific volumetric wear of the coating (for the DLC + 5 % Si coating have the highest values). [ABSTRACT FROM AUTHOR]

[Display omitted] • Physical and mechanical properties were obtained for (1 0 0), (1 1 0) and (1 1 1) oriented Si wafers. • Certain directions of crack propagation were revealed for each orientation. • AFM allowed to obtain crack length and К 1C with high accuracy. • A correlation was established between К 1C , surface energy and Young's modulus. • A correlation was established between G 1C and microhardness H. Crack resistance of silicon wafers plays a vital role in development of MEMS technologies containing beam elements. In the present research, this characteristic was determined using the Vickers tip indentation method. The critical stress intensity factor K IC and fracture energy G IC of silicon wafers of (1 0 0), (1 1 0), and (1 1 1) crystallographic orientations were evaluated. The measurements were supplemented by imaging of indents using atomic force microscopy (AFM). The correlation of these parameters with the specific surface energy, Young's modulus E and microhardness H was conducted. The values of E and H were evaluated by nanoindentation. The dependences of K IC and G IC on the load of silicon wafers of (1 0 0), (1 1 0), and (1 1 1) orientations were obtained. [ABSTRACT FROM AUTHOR]

The sensory properties of monocrystalline quartz are influenced by its surface, mechanical properties, and crack resistance. The surface quality of quartz is significantly influenced by its processing technology. The aim of this work is comparative studies of surface morphology, roughness, mechanical properties, and crack resistance of single-crystal quartz plates after chemical–mechanical and magnetorheological polishing. Surface morphology was assessed by atomic force microscopy (AFM). E and H were determined by nanoindentation (NI). The fracture toughness was assessed by the indentation method with visualization of the AFM imprint topography. The task was to determine the most reliable method for calculating the critical stress intensity factor КIC for quartz, adequate to the load range from 0.01 to 0.5 N. It was found that chemical–mechanical polishing creates an altered layer 70 nm thick on the quartz surface, which significantly changes its mechanical properties and КIC. [ABSTRACT FROM AUTHOR]

Alteration of the phase composition of a coating and/or its surface topography can be achieved by changing the deposition technology and/or introducing additional elements into the coating. Investigation of the effect of the composition of CrN-based coatings (including AlCrN and CrON) on the microparticle height and volume, as well as the construction of correlations between the friction coefficient at the microscale and the geometry of microparticles, are the goals of this study. We use atomic force microscopy (AFM), which is the most effective method of investigation with nanometer resolution. By revealing the morphology, AFM allows one to determine the diameter of the particles, their heights and volumes and to identify different phases in the studied area by contrasted properties. The evaluation of the distribution of mechanical properties (modulus of elasticity E and microhardness H) on the surfaces of multiphase coatings with microparticles is carried out by using the nanoindentation method. It is found that the roughness decreases with an increase in the Al concentration in AlCrN. For the CrON coatings, the opposite effect is observed. Similar conclusions are valid for the size of the microparticles and their height for both types of coating. [ABSTRACT FROM AUTHOR]

• ZrN coatings were grown on the polished steel substrates at the different N flow rate. • Nanocrystalline microstructure of the surface are explored by AFM analysis. • The main texture of ZrN phase changes from (111) to (200) with the increase of N. • E and H were analyzed by nanoindentation. ZrN coatings with the thickness of about 3 μm were deposited on hardened steel substrates by reactive magnetron sputtering at the constant magnetron power of 700 W and at the substrate bias voltage about − 10 V with different nitrogen flow rate from 3 to 6 sccm. The surface investigations were carried out using scanning electron microscopy, atomic-force microscopy, nanoindentation and glancing-angle X-ray diffraction. It was found that the texture of ZrN phase, the mechanical properties and the size of grains in the polycrystalline ZrN coatings can be controlled using different nitrogen flows. [ABSTRACT FROM AUTHOR]

Tools and machine surfaces are subjected to various types of damage caused by many different factors. Due to this, the protecting coatings characterized by the best properties for a given treatment or environment are used. AlCrN coatings with different compositions, synthesized by different methods, are often of interest to scientists. The aim of the presented work was the deposition and investigation of two sets of coatings: (1) formed in nitrogen pressure from 0.8 Pa to 5 Pa and (2) formed at arc current from 50 A to 100 A. We study relationships between the above technological parameters and discuss their properties. Coatings formed at nitrogen pressure (pN2) up to 3 Pa crystallize both in hexagonal AlN structure and the cubic CrN structure. For pN2 > 3 Pa, they crystallize in the CrN cubic structure. Crystallite size increases with nitrogen pressure. The coatings formed at different arc currents have a cubic CrN structure and the crystallite size is independent of the current. The adhesion of the coatings is very good, independent of nitrogen pressure and arc current. [ABSTRACT FROM AUTHOR]