Friction and abrasive surface treatment of engineering steels is the new effective tool for surface material strengthening and improving the resistance to fatigue damage. The specific abrasive machining of medium-carbon steel yields formation of surface hardened layer with super dispersed nanocrystal structure which increase the fatigue damage resistance in times. The present study aimed to est...

The issue of reducing tillage resistance and lowering energy consumption has become increasingly relevant. Strip a positive impact on soil protection reduction. This study analysed the components rotary blades their relationship with operating parameters developed mathematical between (power fuel consumption). We summarised into three parts: air resistance, lateral rotational friction (divided ...

In this study the friction, wear and surface mechanical behavior of medical-grade ultra-high molecular weight polyethylene (UHMWPE) (GUR 1050 resin) were evaluated as a function of polymer crystallinity. Crystallinity was controlled by heating UHMWPE to a temperature above its melting point and varying the hold time and cooling rates. The degree of crystallinity of the samples was evaluated usi...

Atomic force microscopy (AFM) experiments and molecular dynamics (MD) simulations were conducted to examine single-asperity friction as a function of load, surface orientation, and sliding direction on individual crystalline grains of diamond in the wearless regime. Experimental and simulation conditions were designed to correspond as closely as state-of-the-art techniques allow. Both hydrogen-...

The contacts between cohesive, frictional particles with sizes in the range 0.1–10μm are the subject of this study. Discrete element model (DEM) simulations rely on realistic contact force models—however, too much details make both implementation and interpretation prohibitively difficult. A rather simple, objective contact model is presented, involving the physical properties of elastic–plasti...

Nano-scratch and nano-indentation were used to determine hardness, elastic modulus, adhesion, friction and wear resistance of chromium oxide coatings in air and in water. The friction coefficient is higher in water, compared to air, and it increases with the applied normal load, although there are no obvious differences in hardness and elastic modulus in air vs. water. A higher normal load incr...

One of the most fundamental questions in tribology concerns the area dependence of friction at the nanoscale. Here, experiments are presented where the frictional resistance of nanoparticles is measured by pushing them with the tip of an atomic force microscope. We find two coexisting frictional states: While some particles show finite friction increasing linearly with the interface areas of up...

-In this work are shown the results obtained from subjecting copper coated with diamond by triboadhesion to a wearing process with a plane rider. Here it is shown the ratio of the normal to shearing forces, called friction factor, as an indication of the resistance of the surface. Micro-Vickers tests shown a 23.2 % increase of hardness of the coated probes compare to non coated probes. Although...

We have studied PET/0.6 PHB, an alternating copolymer in which PET is poly(ethylene terephthalate) and PHB is p-hydroxybenzoic acid with the mole fraction of 0.6 PHB. It is a longitudinal polymer liquid crystal (PLC) with the LC sequences in the main chain and oriented along the chain backbone. Material not subjected to the magnetic field, specimens oriented along and perpendicularly to the flu...

High dry friction requires intimate contact between two surfaces and is generally obtained using soft materials with an elastic modulus less than 10 MPa. We demonstrate that high-friction properties similar to rubberlike materials can also be obtained using microfiber arrays constructed from a stiff thermoplastic (polypropylene, 1 GPa). The fiber arrays have a smaller true area of contact than ...