TiO_xN_y coatings are known for their good biocompatibility and corrosion resistance and have been previously explored for biomedical applications, including cardiovascular stents. In this work, emphasis is placed on a systematic investigation of the effect of substrate bias voltage on the structural, morphological, and mechanical properties of TiO_xN_y films deposited by reactive magnetron sputtering. TiO_xN_y coatings were deposited on 316L stainless steel substrates using a pure titanium target (99.99%) in an Ar–N₂–O₂ gas mixture at various substrate bias voltages (0 to −150 V). The influence of substrate bias on the deposition rate, structure, and mechanical properties of the films was investigated. X-ray diffraction (XRD) analysis revealed the sequential phase evolution from cubic TiN to oxynitride TiON and further to TiO₂ (anatase/rutile) with increasing negative substrate bias, indicating that ion bombardment energy plays a decisive role in determining the crystallinity and phase composition of the coatings. The coating deposited at −50 V exhibited the highest hardness (~430 HV) and good adhesion strength (critical load 20–25 N). Contact angle measurements confirmed the hydrophilic behavior of the coatings, which is favorable for biomedical applications.

This study investigates the effects of ultrasonic nanocrystalline surface modification (UNSM) on the formation of nitride layers in Ti-6Al-4V alloy during ion-plasma nitriding (IPN). Various UNSM parameters, including vibration amplitude, static load, and processing temperature, were systematically varied to evaluate their influence on microstructure, hardness, elastic modulus, and tribological behavior. The results reveal that pre-treatment with optimized UNSM conditions significantly enhances nitrogen diffusion, leading to the formation of dense and uniform TiN/Ti₂N layers. Samples pre-treated under high-load and elevated-temperature UNSM exhibited the greatest improvements in surface hardness (up to 25%), elastic modulus (up to 18%), and wear resistance, with a reduced and stabilized friction coefficient (~0.55). Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses confirmed microstructural densification, grain refinement, and increased nitride phase intensity. These findings demonstrate not only the scientific relevance but also the practical potential of UNSM as an effective surface activation technique. The hybrid UNSM + IPN approach may serve as a promising method for extending the service life of load-bearing biomedical implants and engineering components subjected to intensive wear.

This study investigates the influence of multilayer architecture on the mechanical, corrosion, and tribological properties of Ti/TiN coatings deposited on biomedical Ti-6Al-4V alloy. Nine multilayer configurations were prepared by DC/RF magnetron sputtering using metallic Ti and ceramic TiN targets, with a fixed TiN/Ti ratio of 3:1 and varying total numbers of layers (3, 5, and 7) and deposition times (30, 60, and 120 min). A strict application of the 10% indentation depth rule was implemented to eliminate substrate effects, which revealed significantly higher intrinsic hardness values (540–740 HV) and indentation moduli (124–143 GPa) compared to the substrate (353 HV; 114 GPa). In contrast, conventional higher-load testing underestimated coating performance due to substrate dominance. Among the investigated architectures, the Ti/TiN-7 configuration exhibited the best balance of properties, combining high hardness (~690 HV), modulus (~137 GPa), improved corrosion resistance (Ecorr up to −0.13 V, Icorr reduced by an order of magnitude), and stable abrasive wear behavior. These findings demonstrate that both bilayer number and deposition time critically determine the mechanical and functional response of Ti/TiN multilayers. The results provide practical guidelines for the reliable characterization and design of multilayer coatings for biomedical and aerospace applications.

This study investigates the influence of preliminary severe plastic deformation on the efficiency of ion-plasma nitriding (IPN) and the formation of a nitrided layer in 12Kh18N10T austenitic stainless steel. Two types of surface mechanical treatment were compared: vibro-impact ball mechanical treatment (VIMT) and ultrasonic nanocrystalline surface modification (UNSM). After the preliminary treatments, the samples were subjected to ion-plasma nitriding at 500 °C for 10 h using ammonia (NH₃) as the working gas. The phase composition, microstructure, elemental distribution, surface roughness, microhardness, and scratch resistance were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS) analysis, profilometry, instrumented indentation, and progressive scratch testing. The results show that both types of preliminary treatment promote the formation of a nitrogen-enriched diffusion layer. The UNSM-treated samples exhibited more pronounced peak broadening and shifting in XRD patterns, indicating a higher level of lattice distortion and nitrogen supersaturation. The maximum nitrogen concentration in the near-surface region reached 15.56 wt.%. Microhardness increased significantly after nitriding for both treatments. Under the selected processing conditions, the UNSM + IPN samples demonstrated a thicker diffusion layer, lower surface roughness, and higher critical loads in scratch testing, indicating improved resistance to surface damage compared with VIMT + IPN samples. The obtained results highlight the important role of the defect structure formed during preliminary treatment in controlling nitrogen diffusion and the resulting mechanical and tribological properties of ion-plasma nitrided austenitic stainless steel.

This chapter is devoted to experimental studies of changes in structural-phase blocks and tribological properties of combustion of layers of high-speed steels R6M5, R9, and R18 during electrolytic-plasma nitriding. Systematized experimental data on the effect of electrolytic-plasma nitriding on the structure, phase composition, and tribological properties of the surface layer of high-speed steels have been obtained. In addition, the patterns of formation of modified layers in high-speed steels during electrolytic-plasma nitriding, revealed in this work, can be used by researchers when choosing the modes of electrolytic-plasma treatment of alloyed steels, as well as when analyzing structural transformations of high-speed steels. Request access from your librarian to read this chapter's full text.

This chapter is devoted to experimental research on the investigated of the structural-phase, morphology, elemental composition, physical-mechanical, and tribological properties (friction, wear, and adhesion) of hard and superhard micro- and nanostructured coatings of systems based on (Zr-Ti-Nb)N, (Zr-Ti-Cr-Nb)N, and (Zr-Ti-Cr-Nb-Si)N were fabricated by vacuum-arc deposition in the nitrogen atmosphere. The authors in the work used advanced proven experimental research methods (SEM-EDX, TEM-EDS, XRD, SIMS, GDMS, PIXE, XPS, AFM, hardness measurements, and adhesion testing), as well as theoretical methods for analysing the results. Based on the results obtained, according to the experimental data, an optimal mode was selected that provides an increase in mechanical and tribological characteristics, and a method for vacuum-arc surface hardening was also developed. Such coatings seem to have prospects as protective ones for couples of friction and cutting tools. Request access from your librarian to read this chapter's full text.