Tribological behavior of eutectic Al-Si based composites in various solutions

The tribological properties of chemical-vapor-deposited (CVD) diamond films vary with the environment, possessing a Jekyll-and-Hyde character. CVD diamond has low coefficient of friction and high wear resistance in air but high coefficient of friction and low wear resistance in vacuum. Improving the tribological functionality of materials (such as achieving low friction and good wear resistance) was an aim of this investigation. Three studies on the surface design, surface engineering, and tribology of CVD diamond have shown that its friction and wear are significantly reduced in ultrahigh vacuum. The main criteria for judging whether diamond films are an effective wear-resistant, self-lubricating material were coefficient of friction and wear rate, which must be less than 0.1 and on the order of 10(exp 6) cu mm/N(dot)m, respectively. In the first study the presence of a thin film (less than 1 micron thick) of amorphous, nondiamond carbon (hydrogenated carbon, also called diamondlike carbon or DLC) on CVD diamond greatly decreased the coefficient of friction and the wear rate. Therefore, a thin DLC film on CVD diamond can be an effective wear-resistant, lubricating coating in ultrahigh vacuum. In the second study the presence of an amorphous, nondiamond carbon surface layer formed on CVD diamond by ion implantation significantly reduced the coefficient of friction and the wear rate in ultrahigh vacuum. Therefore, such surface layers are acceptable for effective self-lubricating, wear-resistant applications of CVD diamond. In the third study CVD diamond in contact with cubic boron nitride exhibited low coefficient of friction in ultra high vacuum. Therefore, this materials combination can provide an effective self-lubricating, wear-resistant couple in ultrahigh vacuum.

Improvement of the tribological properties of steels can be achieved by increasing the hardness of the surface and by reducing roughness and the coefficient of friction. The formation of composite layers on steel, consisting of a hard nitrided or nitrocarburised diffusion layer and an external carbon coating with a low coefficient of friction, seems to be a prospective solution with significant potential. The paper presents an innovative method of producing carbon-based coatings on diffusion layers by means of a low-temperature process utilizing a single device for glow-discharge treatment. 316L austenitic stainless steel, one of the most popular and most readily available single-phase steels, was used in the tests. The layers have been formed in successive processes of nitriding or nitrocarburising in low-temperature plasma followed by deposition of a nitrogen-doped carbon coating under DC glow-discharge conditions. An evaluation was made of the impact of the nitrided and nitrocarburized layers on the properties and morphology of the carbon coatings formed, by comparing them to a coating produced on unpretreated steel substrates. A study of the surface topography, roughness, nanohardness, coefficient of friction, wear, adhesion and corrosion resistance shows a significant importance of the substrate type the coatings are formed on.

Development and performance analysis of novel cast copper–SiC–Gr hybrid composites

High-temperature tribological behavior of Ti containing diamond-like carbon coatings with emphasis on running-in coefficient of friction

Synergistic effect of ferrous sulphide and MWCNT on wear behaviour of HVOF-sprayed nickel/graphite composite coatings

Effect of secondary processing on the microstructure and wear behavior of spray formed Al–30Mg2Si–2Cu alloy

Festkörpergleitreibung und verschleiss von eisen, kobalt, kupfer, silber, magnesium und aluminium in einem sauerstoff-stickstoff-gemisch zwischen 760 und 2 × 10 −7 torr

High temperature wear behavior of NiCoCrAlY-Cr2O3-AgMo coating on GH4169 superalloy

Nanomechanical properties evaluation of chromium nitride films by nanoindentation and nanowear techniques

Hybrid materials, as a consequence of the synergistic effect, enormously tune the electrical, optical, optoelectronic, and other functional properties of various material systems. Recently, layered hybrid materials have largely been sought for greater control of functional properties. However, tribo-engineering with layered hybrid materials has not been well explored and has yet to be fully understood to advance moving mechanical components. Here, we develop a variety of layered hybrid materials based on a combination of multilayer graphene (mGR), multilayer graphene oxide (mGO), boron nitride (BN), and tungsten disulfide (WS2) and probe their tribological effectiveness using a ball-on-disk low-load tribometer. We demonstrate that solution-processed hybrid flakes coatings of BN and WS2 on stainless steel 304 (SS) are not tribologically resilient. However, when combined with mGO and mGR-based compositions, even BN and WS2-based hybrid flakes coatings reveal enhanced tribological performance due to synergistic effects. Developed BN_mGR and WS2_mGO binary hybrids, as well as BN_WS2_mGR and BN_WS2_mGO ternary hybrids, reduced friction by 32%, 59%, 29%, and 40%, respectively, compared to bare SS. We demonstrate that the WS2_mGO binary hybrid flakes coating yields a low coefficient of friction (COF) and high wear resistance. To further enhance its survival under rigorous tribological conditions, particularly at higher loads, we engineer its formulation. The resulting WS2_mGO_14 formulation exhibits the lowest friction with an average COF of ~ 0.09, reducing the friction of bare SS by 87%, and the highest wear resistance at a normal load of 0.1 N. Moreover, it maintained its tribological effectiveness at higher normal loads up to 4 N, outperforming all other hybrid flakes coatings and various other WS2_mGO formulations studied in this work. Microscopic and spectroscopic studies by FESEM, Raman, and FTIR are conducted to gain fundamental insight into friction and wear control mechanisms of the WS2_mGO hybrid. This work discovers that the inclusion of carbon-based layered material is mandatory to achieve low friction and high wear resistance in BN and WS2-based material systems and developing slippery surfaces.

Antifriction coatings based on aromatic phenylene polyamide (phenylone) were developed by introducing a copper arylamide complex with benzimidazole-2-thiocarboxylic acid as a modifying additive. The tribological properties of the phenylene-modifying additive system were investigated, focusing on the nature and concentration of the modifying additive in the polymer composition. The influence of the additive on the microhardness of the polymer coatings was assessed. The introduction of the copper arylamide complex with benzimidazole-2-thiocarboxylic acid as a modifying additive resulted in changes to the polymer matrix structure, forming strong chemical bonds between polymer chains, which improved the strength of materials and reduced its wear susceptibility. The tribological properties of the modified coatings were characterized by a lower coefficient of friction and better wear resistance compared to unmodified coatings. The developed coatings can be widely applied in various industries, such as mechanical engineering, aviation, and automotive, offering benefits such as enhanced durability, wear protection, and reduced maintenance costs. Additionally, their use can contribute to lower energy consumption and reduced environmental impact.

One-step hydrothermal synthesis of reduced graphene oxide/zinc sulfide hybrids for enhanced tribological properties of epoxy coatings

The influence of heat treatment on the microstructure, surface topography and selected properties of PEEK coatings electrophoretically deposited on the Ti-6Al-4V alloy

Tribological Characteristics of Fe-Cu-Sn Alloy with Molybdenum Disulfide as a Solid Lubricant under Dry Conditions

Hexagonal close-packed cobalt-base alloys, if they can be achieved at the required temperatures, could have very desirable creep-strength properties in addition to good wear resistance and low coefficient of friction.