Lubrication of mechanical systems using water instead of conventional oil lubricants is extremely attractive from the view of resource conservation and environmental protection. However, insufficient film thickness of water due to low viscosity and chemical reaction of water with metallic materials have been a great obstacle in utilization of water as an effective lubricant. Herein, the frictio...

The tribological performance of artificial hip joints is a critical issue for their success, because adverse tissue reaction to wear debris causes loosening and failure. Many studies on wear and lubrication of hip prostheses have been published in the last 10 years, mostly on experimental tests. Theoretical/ numerical models have been proposed for investigating geometrical and material paramete...

Ductile metal deformation processes aimed at production of wire of some sort are in use since over five thousand years, early ones dating back to the origins of copper and gold produc­ tion. Thin sheets, initially produced by hammering, were cut into thin strips suitable for ornamental pur­ poses. The introduction of die plate paved the way to round wire manufac­ turing, rather severe limitatio...

METALWORKING consists of deformation processes in which a metal billet or blank is shaped by tools or dies. The design and control of such processes depend on the characteristics of the workpiece material, the conditions at the tool/workpiece interface, the mechanics of plastic deformation (metal flow), the equipment used, and the finished-product requirements. These factors influence the selec...

Viscous heating becomes significant in the high speed resin coating process of glass fibers for optical fiber manufacturing. This study focuses on the coating resin flows inside the capillary coating die of optical fiber coating applicator and they are numerically simulated to examine the effects of viscous heating and subsequent temperature increase in coating resin. Resin flows are driven by ...

A systematic study was carried out to evaluate the correlation between high pressure die casting (HPDC) parameters and the mechanial properties of Magnesium alloys. The tested alloys included two conventional alloys: AZ91D and AM50A and a newly developed alloy, RI153M. The nature of the above correlations was semi-empiric, based on computer simulation of the die casting process using MAGMA® sim...

The purpose of this research paper is to examine the tribological characteristics and issues related to journal bearings under boundary and mixed lubrication conditions during shaft startup, shutdown, and low speeds. The key issues and problems related to journal bearings, most notably wear, are discussed as well as the subsequent issues created in the field. The mechanical analysis of the load...

A lubrication model describes the dynamics of a thin layer of fluid spreading over a solid substrate. But to make forecasts we need to supply correct initial conditions to the model. Remarkably, the initial fluid thickness is not the correct initial thickness for the lubrication model. Theory recently developed in [12, 14] provides the correct projection of initial conditions onto a model of a ...

Lubrication flows appear in many applications in engineering, biophysics, and in nature. Separation of surfaces and minimisation of friction and wear is achieved when the lubrication fluid builds up a lift force. In this paper we analyse soft lubricated contacts by treating the solid walls as viscoelastic: soft materials are typically not purely elastic, but dissipate energy under dynamical loa...