Lubricants, Volume 6, Issue 4

Starved lubrication is an important strategy for minimizing the amount of lubricant needed, and also inevitably occurs during idling and fail-safe lubrication. In this regime, however, the flow of the lubricant and the related friction coefficients a...

Hydrodynamic journal bearings are used within a wide range of machines, such as combustion engines, gas turbines, or wind turbines. For a safe operation, awareness of the lubrication regime, in which the bearing is currently operating, is of great im...

The understanding of rail braking is irrevocably dependent on the tribological analysis of contacts such as the wheel/rail contact or the wheel/brake disc contact. Because it is very complex to experimentally analyze the inside of a contact, a numeri...

Frictional and dynamic responses of brake pad materials, when sliding on brake disc counterfaces, are at the origin of noise, vibration and harshness (NVH) issues such as brake noise emissions. In more detail, groan is a low frequency noise emission...

This study investigates the impact of different surfactants and dispersion techniques on the friction and wear behavior of WS₂ and MoS₂ nanoparticles additives in a Polyalphaolefin (PAO) base oil under boundary lubrication conditions. The nanoparticl...

This paper focuses on the operating behavior of journal bearings for industrial machinery application during run-ups. For this purpose, a numerical simulation code that is based on a two-dimensional extended and generalized Reynolds equation and a fu...

The processes taking place on the friction surface of high-alloyed aluminum alloys working with steel whilst replacing bronze journal bearings with aluminum are investigated. In this regard, eight experimental aluminum alloys with an Sn content from...

The present study investigates the influence of hygrothermal ageing on the tribological behaviour of polytetrafluoroethylene (PTFE) polymer composites. Three PTFE composites along with unfilled PTFE were tested in sliding contact against Inconel 625...

This study is focused on the reduction of CO₂ emissions and costs associated with ultra-low viscosity (ULV) engine oils for passenger vehicles. Specifically, the reduction in life cycle CO₂ (LCCO₂) emissions from lower-viscosity engine oil and the oi...

An understanding of mechanisms which are responsible for elastohydrodynamic lubricant film formation under high sliding conditions is necessary to increase durability of machine parts. This work combines thin-film colorimetric interferometry for lubr...

Reduction of leakage from the shaft–radial lip seal conjunction is critical in ensuring enduring performance of entire lubrication system. This paper investigates leakage from three types of shaft surfaces, finished using different manufacturin...

The use of Environmentally Acceptable Lubricants (EALs) for stern tube lubrication is increasing. Although the machine components of a sailing vessel are designed to operate together with mineral oil-based lubricants, these are being replaced by the...

In recent years, surface texturing in micro-scale has been attempted on the surface of cutting tools for multiple purposes, e.g., cutting force reduction, prolonging life-span, anti-adhesion, etc. With respect to machinability and performance, micro-...

A comparative study between a conventional- and leading edge grooved (LEG) tilting pad journal bearing (TPJB) segment is performed. The developed model uses the Shear Stress Transport (SST) turbulence model, coupled with the energy equation and a par...

In this study, a sliding friction model for coated single asperity contacts is proposed. A displacement-driven layered contact algorithm is firstly introduced and verified by the finite element method. Then, this algorithm is applied to simulate the...

The present work is focused on the numerical solution of the complete energy equation used in fluid film lubrication. The work was motivated by the fact that the complete energy equation has no analytical solution that can be used for validations. It...

Research on the formulation of estolides from plant seed oils has attracted substantial attention due to their favorable low-temperature properties and environmentally friendly nature. The present research investigates the formulation of canola biodi...

A lean duplex stainless steel, LDX2404, was DC plasma nitrided under a range of treatment conditions. The microstructure characterisation evaluation of the treated samples revealed that a dense, super-hard surface layer can be produced by low-tempera...

The effect of steel disc surface texturing on dry gross fretting in a ball-on-disc configuration was studied. Dimples were created with abrasive jet machining. The tribological performance of sliding pairs, steel–steel and steel–ceramics,...

In many industrial applications, a modification of the surface geometry can enhance the tribological behaviour of lubricated sliding contacts. In this paper, the effect of surface texturing on the coefficient of friction in parallel sliding lubricate...

To further improve efficiency in automotive engine systems, it is important to understand the generation of friction in its components. Accurate simulation and modeling of friction in machine components is, amongst other things, dependent on realisti...

Since human body joints have a gel-like structure with low friction that persists for several decades, hydrogels have attracted much interest for developing low-friction materials. However, such advantages can hardly be realized in industrial usage b...

Leakage in static metal-to-metal seals is predominantly determined by the topography of the contacting surfaces. The topography consists of features that span the entire range from its carefully engineered geometry down to micro-sized surface asperit...

The study of textured surface performance is one of the highly researched topics in recent times. This is mainly due to the advantages that such surfaces can potentially provide in practice, in mitigating adverse tribological conditions, such as fric...

Titanium use is limited due to its poor tribological properties, and thermal oxidation (TO) and pack carburisation with limited oxygen diffusion (PCOD) are just two of the surface treatments that can be used to enhance the surface properties of Ti. I...

True contact between solids with randomly rough surfaces tends to occur at a large number of microscopic contact patches. Thus far, two scaling regimes have been identified for the number density $n\left(A\right)$ of contact-patch sizes A in elastic, n...