Lubricants, Volume 6, Issue 2

Nanodiamonds are known to improve tribological performance when added to lubricants, but their impact on additives that may already be present in the lubricant is poorly documented. Here, we report on a study of their effects on thermal reaction film...

Vegetable oil-in-water (VO/W) emulsions are bio-based metal working lubricants. The emulsions’ lubrication performance depends on the stability of oil droplets. In this paper, the oil droplets’ dispersion stability and lubrication of emul...

The running-in of lubricated metal–metal contacts leading to ultra-low wear is inseparably connected with the formation of the third body and vice versa. Adequate tribological stressing provides the system with a power density that leads to com...

Drag reduction technologies mainly include the mechanical method and the chemical method. Mechanical drag reduction technologies are widespread in the drilling field due to their environmental friendliness and ease of use. Vibration technologies are...

Among the possible solutions for achieving low friction, polymer brushes that are grafted onto surfaces are good candidates. The tribological characterization of such layers becomes more difficult when the friction is lower: the signal-to-noise ratio...

Conventionally discussed dynamic mechanisms of elastic strain energy redistribution in near-contact surface regions include P and S elastic wave pulses radiating from the contact surface. At the same time, the elastic strain energy can be transferred...

The hydrodynamic lubrication and thermal analysis of tilting pad thrust bearings has been a major subject for many studies in the field of tribology. There is only a limited number of studies regarding thrust bearings with coated surfaces. The purpos...

In this article, a geometrical model of different microtextures is established for an axial piston pump valve plate. A finite differential method was used to solve the Reynolds equation for the oil film thickness and pressure, which were simulated un...

Mo and Al₂O₃-Mo coatings are fabricated on a low-carbon steel substrate using atmospheric plasma spraying. The microstructure and mechanical properties of two as-sprayed coatings, with a particular focus on the tribological behaviors from room temper...

Three main concerns are in the focus of the development of geared transmissions nowadays: load carrying capacity, noise–vibration–harshness (NVH) behavior, and efficiency. Increasing the efficiency of modern gearboxes contributes significantly to the...

This paper deals with an efficient 3D modelling of a radial ball bearing to predict the operating lubrication regime under mechanical loading and mounting conditions by using the Discrete Element Method (DEM). Due to the relevance of such an approach...

Against the background of raw material shortage and the ever-expanding environmental consciousness, the use of biodegradable greases becomes more and more important. The aim of this experimental work is to investigate the tribological response of com...

The principle energy exchange of a brake system occurs in the tribological boundary layer between the pad and the disc. The associated phenomena are primarily responsible for the dynamics of brake systems. The wear debris forms flat contact structure...

The sliding behavior of an amorphous silica sample between two rigid surfaces is in the focus of the present paper. Molecular Dynamics using a classical Tersoff’s potential and a recently developed ReaxFF potential was applied for simulating sl...

This paper presents a systematic procedure for the development of a constitutive model of friction with focus on the application in bulk metal forming simulations. The empirically based friction model describes friction as a function of sliding dista...

The precise knowledge of frictional behavior is highly relevant for accurate modelling in sheet metal forming simulations. This allows e.g., the precise prediction of restraining forces which, in turn, determines an optimal draw bead strategy and bla...

Due to requirements of their operating conditions, such as high speed, high flexibility and high efficiency, rotating machines are designed to obtain larger operating ranges. These operating conditions can increase the risk of fluid-induced instabili...

Nowadays, hydropower plants are forced to have more frequent power control and the self-lubricated bearings used in the applications are one of the most critical components affected by the continuously changing operating conditions. In this study, mi...

An arc-sprayed Fe-based amorphous coating with high hardness and low porosity was prepared. A tribo-electrochemical approach was used to study the tribocorrosion behaviour of the amorphous coating. The volume wear losses of the amorphous coating with...

In the design and development of rubber products, it is important to evaluate the contact load dependency of the friction coefficient. In particular, since the pressure distribution varies depending on the dimensions of sliding bodies and the pattern...

Laser surface texturing is an efficient way to control the friction and wear properties of materials. Although described in many papers, most previous work relates to a pure topographic view of laser-textured surfaces. As lasers are heat sources, the...

Using Fourier transform infrared (FT-IR) spectroscopy we investigated the water content of SAE 15W–40 diesel engine lubricating oil at various levels of contamination to establish instrument calibration standards for measuring water contamination in...

The challenges of technical systems subjected to friction and wear become more demanding with steadily increasing stresses. Besides safety matters, failure of tribologically loaded systems can cause tremendous maintenance costs. Because of the lack o...

A stretching behavior of knitted and woven textiles is modeled. In our work, the yarns are modeled as one-dimensional hyperelastic strings with frictional contact. Capstan law known for Coulomb’s friction of yarns is extended to an additional adhesio...

The service life of rolling bearings is significantly affected by the film formation in elastohydrodynamic (EHD) contacts, which depends on the operating conditions, like rotational speed or temperature. In grease lubricated EHD contacts, the film fo...

We performed, for the first time to our knowledge, fully ab initio molecular dynamics simulations of additive tribochemistry in boundary lubrication conditions. We consider an organophosphourus additive that has been experimentally shown to reduce fr...

Articular cartilage surrounds the ends of diarthrodial joints (most common movable joints) and during motion, it experiences a wide range of loading conditions while remaining under exceedingly low-friction and wear-free conditions. This remarkable t...