This article explores the properties of composite materials employed in dental fillings. A traditional nano-hybrid composite containing nanofiller particles exceeding 82% by weight served as a benchmark. The remaining samples were fabricated from ormocer resin, maintaining an identical nanofiller content of 84%. In all specimens, the nanoparticles were dispersed randomly within the matrix. This study presents findings from investigations into surface geometry, hardness, wettability, and tribological behavior. The microscopic observations revealed that ormocer-based samples exhibited greater surface roughness than those composed of the traditional composite. Hardness testing indicated that both ceramic addition and sample preparation significantly influenced mechanical properties. Ceramic-enhanced samples demonstrated superior hardness, surpassing the reference composite by 30% and 43%, respectively. Contact angle measurements revealed hydrophilic characteristics in the classic composite, contrasting with the hydrophobic nature of ceramic-containing samples. Tribological evaluations revealed the superiority of the classic composite in terms of friction coefficients and volumetric wear compared to ormocer-based materials.

Clinical trials conducted in many centres worldwide indicate that, despite advances made in the use of biomaterials for medical applications, tribocorrosive wear remains a significant issue. The release of wear residue into body fluids can cause inflammation and, as a result, implant failure. Surface modification is one of the methods used to improve the mechanical, tribological, and fatigue properties of biomaterials. In this article, the authors investigated the impact of ion implantation on improving the functional properties of implant surfaces. This paper presents morphology, geometric surface structure, hardness, and tribological test results for layers obtained by ion implantation with nitrogen and oxygen ions on alloy 316L. The surface morphology and thickness of the implanted layer were examined using scanning microscopy. Atomic force microscopy was used to evaluate the geometric structure of the surface. Instrumented indentation was used to measure nanohardness. Model tribo tests were carried out for reciprocating motion under conditions of dry friction and lubricated friction with Ringer’s solution. The tribological tests showed that the implanted samples had a lower wear than the reference samples. Nitrogen ion implantation increased the hardness of 316L steel by about 45% and increased it by about 15% when oxygen ions were used.

This study investigates the properties of diamond-like carbon (DLC) coatings deposited onto a Ti6Al4V titanium alloy using plasma-assisted chemical vapor deposition (PACVD). The research encompasses adhesion tests, hardness, surface characterization, as well as corrosion and tribological evaluations. Artificial saliva was employed as both the lubricating and corrosive medium. Microscopic examination revealed a uniform coating with a thickness of about 3.2 µm. Scratch test results indicated that the deposited DLC coating exhibited superior adhesion, lower frictional resistance, and reduced wear compared to the titanium alloy. The coating deposition increased the hardness of the Ti6Al4V alloy by about 75%. Friction coefficients, measured under dry and lubricated conditions, were approximately 80% lower for the DLC-coated samples. Corrosion studies revealed that both the coated and uncoated surfaces demonstrated typical passive behavior and high corrosion resistance in artificial saliva. For DLC coatings, the corrosion current density and the corrosion rate were reduced by 85%. Microscopic observations of wear tracks following tribological and scratch tests confirmed the inferior wear and scratch resistance of the titanium alloy relative to the DLC coating. Under both dry and lubricated conditions (with artificial saliva), the volumetric wear rate of the titanium alloy was over 90% higher than for the DLC coating.

In this paper, the authors investigated the impact of DLC coatings doped with tungsten (a-C:H:W) coatings obtained using plasma-assisted physical vapor deposition (PVD) on the properties of the 100Cr6 steel. The results of the 100Cr6 steel specimens with and without the coating were compared. Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis were used to observe the morphology of the coating surfaces and cross-sections and identify the elements in the coating composition. The contact angle of the investigated surfaces was measured with a tensiometer. Additionally, the effect of the coatings on the tribological properties of lubricated friction pairs was evaluated. Friction tests were performed on a ball-on-disc tribometer under lubrication with cutting fluid. The surface texture of the samples before and after the tribological tests was measured using a confocal profilometer. The results obtained from the tests and analysis allow for the conclusion that the use of DLC coatings a-C:H:W increases the hardness of 100Cr6 steel by three times. The values of the contact angles were indicative of surface hydrophilic characteristics. The tungsten-doped diamond-like coating under friction conditions reduced the coefficient of friction and wear. DLC coatings a-C:H:W lubricated with the cutting fluid improve the mechanical and tribological properties of 100Cr6 steel sliding surfaces under friction.

This paper evaluates surface roughness effects on the properties of a-C:H:Si coatings obtained using plasma-assisted chemical vapor deposition (PACVD). Prior to coating deposition, the surfaces of the samples were subjected to grinding (Ra = 0.25) and then polishing (Ra = 0.05) or sandblasting (Ra = 1.41). Microscopic observations, measurements of thickness, wettability, surface topography, and tribological tests were used to characterize the substrate. The coating microstructure, thickness, and chemical content were investigated using scanning electron microscopy with energy dispersive spectroscopy (EDS). The geometric structure of the surface was examined using confocal microscopy before and after tribological tests. Tribological studies used a ball-on-disk sliding configuration in reciprocating motion under dry friction and cutting oil lubrication. The values of the contact angles were indicative of surface hydrophilic characteristics. Compared with the sandblasted surfaces, the adhesion strength of the coatings deposited on the polished surfaces was found to be higher. The coatings contributed to the improvement of friction and wear parameters. Under dry friction, a-C:H:Si coating friction coefficients and linear and volumetric wear on the polished surface were reduced compared with the sandblasted surface, respectively, by 10%, 83%, and 85%. In addition, the lubricant contributed to reducing the friction coefficients of the coating applied to the sandblasted sample compared with the polished sample without the coating by about 94%. Microscopic observations of wear traces allowed the determination of wear mechanisms; in the case of Ti13Nb13Zr, it was tribochemical wear through oxidation, while in the case of coatings, scratching and microcutting dominated.

This study aims to characterise TiCN coatings deposited on Ti6Al4V by physical vapour deposition. Findings on surface morphology, geometric structure, adhesion, instrumental hardness, and tribology are presented. Microscopic examination revealed a uniform coating with a thickness of about 1.5 µm and roughness (Sq) equal to 0.13 µm. Mechanical tests showed that the coating deposition increased the hardness of the Ti6Al4V alloy by about 75%. The artificial saliva solution used in the tribological tests reduced the coefficient of friction and the volumetric wear of the tested friction pairs. Microscopic observations of wear tracks after tribological tests allowed for the identification of wear mechanisms: micro-cutting/ploughing wear dominated in both the Ti6Al4V alloy and TiCN coating samples, but wear was much less pronounced overall with the TiCN coating. The study results demonstrate that the deposition of a TiCN coating simultaneously imparts low-friction and anti-wear properties to the surface of titanium alloys.