In this work, the TiO₂ coatings were synthesized by electrophoretic deposition (EPD) of nano-sized powder in order to improve the tribological properties. Several characterization methods were applied to the coated substrates. The surface topography of the EPD layers, their morphology, composition and mechanical properties were investigated. The influences heat treatment, which results in calcination, on the wear performance of coated films was also examined. It was noticed that the effect of the normal force and sliding velocity on the coefficients of instantaneous and stabilized friction was not the same in treated coatings and untreated ones. Moreover, the treated and uncoated films showed a close relation between the dissipated accumulated energy and the worn volume. The energetic wear coefficients of fretting wear were also studied. As expected, the treated coating reduced the energetic wear coefficient, which enhanced the resistance to fretting wear.

In this study, chromium nitride-based CrSiN coatings were deposited by PVD (physical vapour deposition) magnetron sputtering on XC100 steel substrate. Mechanical properties of CrSiN were investigated using monotonic nanoindentation test. It was found that CrSiN coatings had excellent mechanical properties, hardness of 30.52 ± 1.85 GPa and elastic modulus of 338.32 ± 13.5 GPa. Fatigue behaviour of CrSiN thin film was studied using multi-cycles nanoindentation test. Under cyclic nanoindentation, the unloading–reloading paths produced the hysteresis loops which reflect a fatigue effect. In addition, the increase in the number of indentation cycle induced the degradation of the film mechanical proprieties and the evolution of damage mechanism. The similarity between the indentation fatigue depth propagation and the conventional fatigue crack growth was exploited based on Manson–Coffin law to extract the fatigue properties of CrSiN coating. The obtained fatigue ductility coefficient was ${\epsilon }_{\mathrm{ind}}^f=0.17$ and the fatigue ductility exponent was c = −0.96.

Conductive PLA is an innovative composite material that combines the ecological benefits of polylactic acid, a biodegradable thermoplastic, with electrical conductivity properties. Usually used in additive manufacturing for its ease of printing and low environmental impact, PLA remains an insulator, which limits its applications in the electrical field. To overcome this limitation, conductive fillers such as carbon nanotubes or carbon black are being added, opening the way to new functional uses. This study focuses on a specific composite: carbon black-filled PLA (PLA-CB). This material combines the qualities of traditional PLA with enhanced conductivity thanks to the carbon black particles. To assess its performance, a number of mechanical tests were carried out, including tensile tests on samples manufactured by 3D printing using the FFF process. The study focused in particular on the influence of crosshead speed and the impact of different notch shapes on the material's properties. To analyze the durability of PLA-CB, a probabilistic model based on the two-parameter Weibull distribution was used to assess the risk of failure under different conditions. Reliability curves were also established to better understand the tensile stress and strain at break of the material. This approach could also be applied to other 3D-printed polymers to refine their analytical and numerical modeling.