22.05.2017 tribonet 262 Views
The ASTM definition of lubricating grease is: “A solid or semi-solid lubricant consisting of a thickener agent in a liquid lubricant. Other ingredients imparting special properties may be included” A commercial lubricating grease usually consists […]
Industrial Lubrication

What Are Lubricants?

17.04.2017 tribonet 627 Views
Definition Lubricant is a substance which is used to control (more often to reduce) friction and wear of the surfaces in a contact of the bodies in relative motion. Depending on its nature, lubricants are […]
Hydrodynamic Lubrication

Hydrodynamic Lubrication

16.02.2017 tribonet 1060 Views
Definition Hydrodynamic lubrication theory is a theory used to reduce friction and/or wear of rubbing solids with the aid of liquid lubricant. For a vast majority of the surfaces encountered in nature and used in […]
Elastic Deformation

Elastic Deformation

16.02.2017 tribonet 719 Views
Definition Elastic deformation is a change of the shape of the body as a reaction to applied stress. This deformation is only temporary and once the stress is released, the undeformed shape of the body […]
EHL film meniscus

Elastohydrodynamic Lubrication (EHL)

05.02.2017 tribonet 1461 Views
Definition of EHL Elastohydrodynamic Lubrication – or EHL – is a type of hydrodynamic lubrication (HL) in which significant elastic deformation of the surfaces takes place and it considerably alters the shape and thickness of […]
Fatigue Surface Crack

Rolling Contact Fatigue

25.01.2017 Aydar Akchurin 1005 Views
Rolling-contact fatigue (RCF) is defined as a failure or material removal driven by crack propagation caused by the near-surface alternating stress field.  It is typically considered that if a bearing is properly mounted, aligned, lubricated, […]
Osborne Reynolds

Generalized Reynolds Equation: Derivation

14.01.2017 tribonet 802 Views
Reynolds equation is one of the fundamental equations of lubrication theory and tribology. In the simplest case, it considers incompressible and Newtonian lubricant. This model is sufficient to describe lubricant friction in some cases (relatively […]
Fatigue Wear

Fatigue Wear

08.01.2017 tribonet 706 Views
Fatigue wear is a type of wear where a number of cycles is needed to generate debris. The fatigue process in metals may induce the generation of surface and subsurface cracks, which after a critical […]
Greenwoods Contact Model

Greenwood and Williamson Contact Model

04.01.2017 tribonet 1108 Views
Surface roughness was recognized to play a major role in forming friction and transition from one lubrication regime to another [1]. Greenwood pioneered with first rough contact model in 1966 [2]. Inspired by this milestone […]
Wear Particle Image

Wear Particles

06.12.2016 tribonet 704 Views
The wear process results in generation of debris, or particles, of various size, shape, color distributions and chemical composition[1, 2, 3]. These distributions are dependent on normal load, sliding speed, environment and many other parameters[4]. […]