The increasing global environmental awareness, evidenced by recent worldwide calls for control of climate change and greenhouse emissions, has placed significant new technical mandates for automotives to improve engine efficiency, which is directly related to the production of carbon dioxide, a major greenhouse gas. Reduction of parasitic losses of the vehicle, powertrain and the engine systems is a key component of energy conservation. For engine efficiency improvement, various approaches in...

The ester base oil of dioctyl adipate (DOA) was oxidized in an oven at 200 ℃ for 30 h, and variations in the physicochemical and tribological properties were studied. To investigate the thermal-oxidation mechanism, the thermal-oxidation products were analyzed by gas chromatography–mass spectrometry (GC−MS), and the thermal-oxidation process was simulated using visual reactive force field molecular dynamics (ReaxFF MD). The results indicated that the total acid number (TAN) incre...

In this study, microsized and nanosized silicon carbide particles (SiCps) were successfully incorporated into commercial pure copper to form a surface metal matrix composite by friction stir processing (FSP) at low-heat-input conditions. A cluster of blind holes on a copper plate was used as particle deposition technique during the fabrication of the composite. Pin-on-disc testing was performed under dry sliding conditions to determine the wear characteristics of prepared composite surfaces. ...

In this study, we investigate the friction between a one-dimensional elastomer and a one-dimensional rigid randomly rough surface. Special emphasis is laid on the temperature dependence of the elastomer and its effect on the frictional behavior of the contact. The elastomer is modeled as a Kelvin body in a one-dimensional substitute model in the spirit of the method of dimensionality reduction. The randomly rough surface is a self-affine one-dimensional fractal. We provide a short discussion ...

The use of two-dimensional shape parameters to characterize abrasive particles is a potential approach to express their angularity. Nevertheless, in sliding abrasion, especially in pin abrasion testing, these descriptors could not be suitable for characterizing severe wear of engineering materials such as steels and cast irons. This work compares the applicability of two-dimensional shape parameters in describing severe wear of metals in recent pin abrasion tests with cases where they could h...

This paper reports a comparative study on the tribological characteristics of base oils in four groups, synthetic esters, mineral oils, polymerized alpha olefins (PAOs), and poly alkylene glycols (PAGs), by means of viscosity, friction, and wear measurements. Friction coefficients for the lubricants in each group, measured with a pin-on-disk tribometer, are summarized in the form of Stribeck curves. Wear of the disk specimens due to rubbing in the interfaces lubricated with the tested oils is...

In this study a wear track was generated on aluminium by rubbing it against a hard steel ball. The generated wear track has a typical depth of 50 μm and exhibits marked ridges on its borders. The cross section profiles were measured using two different stylus profilometers equipped either with skidless or skid probes and compared to a skidless reference instrument. It was found that the use of a skid probe can introduce significant distortion of the measured wear track profiles and thus error...