Among the alternatives for using low-carbon steel in parts with heavy wear, as gears and bearing surfaces, Ni-B electroless coatings deposited on these steels are considered due to their wear resistance. Wear maps, elaborated from friction or wear results found for different evaluated conditions, are a very useful tool for the selection of materials based …
Month: June 2019
An elastohydrodynamic lubrication model for a rigid ball in contact with a transversely isotropic half-space is constructed. Reynolds equation, film thickness equation, and load balance equation are solved using the finite difference method, where the surface vertical displacement or deformation of transversely isotropic half-space is considered through the film thickness equation. The numerical methods are …
Element 35 in our International Year of the Periodic Table series is bromine. One of only two elements in the periodic table that are liquids at room temperature, its compounds are used as flame retardants and were historically used in dyes. Bromine is the only non-metal which is a liquid at room temperature. It’s a …
Frictional properties of a self-lubricating nanocomposite material with an A–OOO polyimide matrix reinforced by gas-phase synthesized tungsten diselenide (WSe2) nanoparticles are studied with a homemade low sliding speed tribometer. Tungsten diselenide is often used as a solid lubricant due to its layered structure yielding to anisotropy, which enhances lubrication properties. To facilitate molecular adhesion friction …
In this study, friction and evolution of cohesive failures (cracks and spallations) in CoB/Co2B layers were analyzed. Thermochemical treatment was carried out at 950, 975, and 1000 °C during 6, 8, and 10 h of exposure time, respectively. The characterization techniques include scanning electron microscopy (SEM) for morphology inspection of layers and thickness measurement, X-ray …
In this study, friction and evolution of cohesive failures (cracks and spallations) in CoB/Co2B layers were analyzed. Thermochemical treatment was carried out at 950, 975, and 1000 °C during 6, 8, and 10 h of exposure time, respectively. The characterization techniques include scanning electron microscopy (SEM) for morphology inspection of layers and thickness measurement, X-ray …
Here’s the monthly summary of chemistry stories that have hit the news. This month features news on a method for converting plastic bottles into jet fuel components, a new record for the longest half-life ever measured, and more! Larger summary images for each item are provided below, along with links to articles and studies for …
Element 34 in our International Year of the Periodic Table series is selenium. Named after the moon, selenium compounds pop up in shampoos and are also partly responsible for the awful smell of skunk spray. If you use a shampoo that boasts of anti-dandruff properties, then it might well contain selenium disulfide. This compound has …
Element 34 in our International Year of the Periodic Table series is selenium. Named after the moon, selenium compounds pop up in shampoos and are also partly responsible for the awful smell of skunk spray. If you use a shampoo that boasts of anti-dandruff properties, then it might well contain selenium disulfide. This compound has …
Various solutions for the design of oil-free bearings are discussed in the literature. Adding hydrodynamic preload to the foil bearings by profiling the inner bore of the bearing is one of the most frequently investigated methods for improving the bearing stability and damping character of the entire system. However, this approach leads to a reduced …
