Nano-lubricants offer improved tribological properties in many applications, such as machines and engines. The presence of nanoparticles in the lubricating oil affects its wear, friction, thermal, chemical and physical properties in many ways. Titanium dioxide (TiO₂) is a promising lubricant additive for enhanced engine efficiency. This article reports the effect of 10 W-30 pure base engine oil suspended TiO₂ nanoparticles. Four different volume concentrations (0.01%, 0.025%, 0.050% and 0.075%) of TiO₂ nanoparticles in the base lubricating oil are used for the analysis. The tribological tests were performed at ambient temperature as well as at 75 °C using a four ball tribometer. Scanning electron microscope (SEM) and Alicona Inginite Focus G5 microscope were used to analyze the worn surface. The results show that the surface-modified TiO₂ nanoparticles can remarkably improve the load-carrying capacity, the friction reducing, and anti-wear abilities of the additive oil. The diameter of the wear trace and the coefficient of friction are the tribological properties analyzed for the nano-lubricant prepared at different volume concentration (VC). It was found that the diameter of the wear scar and the coefficient of friction increase with increasing VC of TiO₂ nanoparticles in the lubricating oil. The main objective of the paper is to present the recent progress and, consequently, to develop a comprehensive understanding of the tribological behavior of engine oil mixed with TiO₂ nanoparticles.

Friction and wear experiments were performed on carbon fiber-reinforced polymer (CFRP) composites, and the tribological behavior of these materials under boundary lubrication (based on the 5100 4T 10 W-30 engine oil with TiO₂ Degussa P25 nanoparticles) was investigated. Experiments were carried out in two directions: one at a different normal load from 6 to 16 N and one at a low sliding speed of 110 mm/min under boundary lubrication conditions. The obtained results reveal the stick-slip effect and the static and dynamic coefficient of friction decreased slightly with increasing normal applied load on the carbon fiber reinforced polymer composite pairs. The second direction highlights through experimental tests on the pin on disc tribometer that the friction coefficient increases with the increase in normal load (20–80 N) and sliding velocity (0.4–2.4 m/s). On the other hand, it is found that the friction coefficient is slightly lower than in the stick-slip phase. During the running-in process, the friction coefficient of the CFRP pair increases steadily as the rubbing time increases, and after a certain rubbing period, it remains constant regardless of the material of the counter face. The obtained results show that for the observed interval, the influence of normal load and sliding velocity have relatively small fraction coefficients and low wear depths. A 3D analysis of the profile demonstrated the texture of wear marks and tracks of these engineering composite materials. Furthermore, the height variations of wear marks and the morphologies of the worn surfaces of specimens under boundary lubrication conditions were analyzed.

The microelectronic industry has been growing rapidly over the past 10-20 years, as has its reliance on thin-film deposition techniques for components manufacturing. As modern devices generate quite a bit of heat and peak temperatures can reach over 100°C, there is a need to provide adequate cooling for a device to stay operable. A series of chrome gold films with various thicknesses were prepared on silicon substrate. The structural and surface morphology, adhesion, friction, Young's modulus and hardness of this thin film were studied for three different thicknesses under temperature variations between 20 to 100 o C. The variation of the film thickness and temperature affects the structure, surface and mechanical properties of Cr/Au thin films. Obviously these thermal cycles are unavoidable and eventually lead to thermal fatigue damage and device failure. Consequently, the knowledge of mechanical properties of thin films at elevated temperatures is required for proper chip design and reliability assessments. Elastic modulus and hardness are two important mechanical properties of the thin-film structural materials used in microelectromechanical systems. The mechanical properties of electroplated chrome-gold thin film are found to be highly dependent on the manufacturing process and also of the thin film thickness. On the other hand it is important to find the effect of temperature on these properties. Investigated samples are made of thin layers of chromium and gold with differences in thickness. The three levels of nominal thicknesses of Au films are: 100, 300 and 500 nm. In order to obtain the relations between surface pattern/surface chemistry and nanotribological properties and adhesive behaviors of the films were evaluated with a noise-and vibration-isolated and environment-controlled XE 70-AFM from Park Systems, using the contact mode. The tests were performed at temperatures between 10 o C-100 o C and at a relative humidity RH of 40%. Each measurement was repeated many times in order to improve the accuracy of the experimental results.

Tribo-mechanical experiments were performed on Glass Fiber Reinforced Polymer (GRFP) composites against different engineering materials, and the tribological behavior of these materials under dry conditions was investigated. The novelty of this study consists of the investigation of the tribomechanical properties of a customized GFRP/epoxy composite, different from those identified in the literature. The investigated material in the work is composed of 270 g/m² fiberglass twill fabric/epoxy matrix. It was manufactured by the vacuum bag method and autoclave curing procedure. The goal was to define the tribo-mechanical characteristics of a 68.5% weight fraction ratio (wf) of GFRP composites in relation to the different categories of plastic materials, alloyed steel, and technical ceramics. The properties of the material, including ultimate tensile strength, Young’s modulus of elasticity, elastic strain, and impact strength of the GFPR, were determined through standard tests. The friction coefficients were obtained using a modified pin-on-disc tribometer using sliding speeds ranging from 0.1 to 0.36 m s⁻¹, load 20 N, and different counter face balls from Polytetrafluoroethylene (PTFE), Polyamide (Torlon), 52,100 Chrome Alloy Steel, 440 Stainless Steel, and Ceramic Al₂O₃, with 12.7 mm in diameter, in dry conditions. These are commonly used as ball and roller bearings in industry and for a variety of automotive applications. To evaluate the wear mechanisms, the worm surfaces were examined and investigated by a Nano Focus—Optical 3D Microscopy, which uses cutting-edge μsurf technology to provide highly accurate 3D measurements of surfaces. The obtained results constitute an important database for the tribo-mechanical behavior of this engineering GFRP composite material.