The evolution of a friction surface geometry with initially directed microscale grooves on a nanoscale polished surface in ring-on-block sliding contact is studied experimentally. Reduced wear and friction is observed when the orientation of grooves coincides with the direction of sliding. A new compressive-vacuum hypothesis of friction force nature under a condition of boundary lubrication is ...

In this article, the mechanical and three body abrasive wear behavior of Bidirectional and short Kevlar fiber reinforced epoxy composites at five different fiber loading (10wt%, 20wt%, 30wt%, 40wt% and 50wt%) have been evaluated. The mechanical properties i.e. tensile strength, flexural strength, inter-laminar-shear strength, and impact strength are performed to notice the behavior of mechanica...

Ultralow wear nature of gallium nitride (GaN) has been revealed recently. The wear rate for GaN has a significant dependence on humidity, ranging from 9 10 9 mm3/Nm to 9.5 10 7 mm3/Nm; the mechanisms responsible for this variation in wear remain unclear. Here, we performed reciprocal sliding test on GaN under different environments and characterized the chemical compositions of corresponding wo...

The authors report the direct observation of a single asperity tungsten tip sliding on graphite by in situ transmission electron microscopy TEM nanomanipulation. The in situ TEM studies have confirmed that graphitic flakes transfer to a sliding tungsten probe, validating proposed friction mechanisms explaining the unique tribological properties of graphite. Wear of graphite was observed, typica...

wear is a complicated phenomenon caused by the relative movement of two contacting surfaces compressed together by a normal force. prediction of the wear, in most cases, requires various experiments and microstructural characterization of the contacting surfaces. mathematical models based on physical concepts could provide considerable help in understanding the physical behavior and hence the p...

The impressively low friction and wear of diamond in humid environments is debated to originate from either the stability of the passivated diamond surface or sliding-induced graphitization/rehybridization of carbon. We find ultralow friction and wear for ultrananocrystalline diamond surfaces even in dry environments, and observe negligible rehybridization except for a modest, submonolayer amou...

Sv. S. Kvon, V. Y. Kulikov, T. S. Fillippova, А. Е. Omarova, Karaganda State Technical University, Karaganda, Kazakhstan This paper deals with service conditions of shaft equipment, in particular, inserts of sliding bearings for the purpose of increasing service life due to material substitution and wear resistance increase. As a new material high-chromium irons are offered. Studies are conduct...

For a large number of non-oxide ceramic/metal as well as for non-oxide particulate reinforced composite/metal tribocouples, oxidative wear is reported to play a major role in the overall damage and material removal process. The designing of new materials with improved resistance to oxidative wear requires understanding of the combined effect of the material properties and operating parameters o...

The wear of cental amalgam was studied by single- and double-pass sliding and by a silicon carbide abrasion test. A dispersed amalgam showed significantly better resistance to two-body abrasion than the spherical amalgams tested. The wear amalgam was determined by resistance to penetration and by a ductile mode of surface failure over the load range studied. Differences in the wear of amalgam a...