The fundamentals of coating tribology are presented in a generalised holistic approach to friction and wear mechanisms of coated surfaces in dry sliding contacts. This is based on a classification of the tribological contact process into macromechanical, micromechanical, tribochemical contact mechanisms and material transfer. The tribological contact process is dominated by the macromechanical mechanisms, which have been systematically analysed by using four main parameters: the coating-to-substrate hardness relationship, the film thickness, the surface roughnesses and the debris in the contact. The description covers both soft and hard coatings with thicknesses typically in the range 0.1–50 μm, where the interaction between the coating and the substrate is essential to the tribological behaviour. The concept is supported by experimental observations. The important influence of thin tribo- and transfer layers formed during the sliding action is shown. Optimal surface design both regarding friction and wear can be achieved by new multilayer techniques giving reduced stresses, improved adhesion to substrate, more flexible coatings and harder and smoother surfaces. The differences in contact mechanisms in dry, water- and oil lubricated contacts with coated surfaces is illustrated by experimental results from diamond-like coatings sliding against a steel ball. The mechanisms of the formation of dry transfer- and tribolayers and lubricated boundary and reaction films are discussed.

Tribology of thin coatings

In this paper, the hardness and wear properties of pure ceramic particles like silicon carbide, boron carbide and graphite are considered in micron size with the reinforced aluminium LM30 m...

Effect of reinforced aluminium alloy LM30 with pure ceramic particles to evaluate hardness and wear properties

Biomass-derived ultrathin mesoporous graphitic carbon nanoflakes as stable electrode material for high-performance supercapacitors

Biomass-derived carbon materials (BCMs) are encountering the most flourishing moment because of their versatile properties and wide potential applications. Numerous BCMs, including 0D carbon spheres and dots, 1D carbon fibers and tubes, 2D carbon sheets, 3D carbon aerogel, and hierarchical carbon materials have been prepared. At the same time, their structure-property relationship and applications have been widely studied. This paper aims to present a review on the recent advances in the controllable preparation and potential applications of BCMs, providing a reference for future work. First, the chemical compositions of typical biomass and their thermal degradation mechanisms are presented. Then, the typical preparation methods of BCMs are summarized and the relevant structural management rules are discussed. Besides, the strategies for improving the structural diversity of BCMs are also presented and discussed. Furthermore, the applications of BCMs in energy, sensing, environment, and other areas are reviewed. Finally, the remaining challenges and opportunities in the field of BCMs are discussed.

Biomass-Derived Carbon Materials: Controllable Preparation and Versatile Applications.

A comprehensive review of parabolic trough solar collectors equipped with turbulators and numerical evaluation of hydrothermal performance of a novel model

Spherical activated-carbon nanoparticles derived from biomass green tea wastes for anode material of lithium-ion battery

Silicon nitride (Si3N4) is a widely used reinforcement material to improve the mechanical properties of the aluminium matrix composites. Aluminium alloy (AA 6063) matrix composite was produced with different wt% of Si3N4 content through stir casting route. L27 orthogonal array was used to conduct the wear test in Pin-on-disc apparatus. The wear parameters were optimized by S/N ratio and ANOVA analysis. SEM images of the composites show the uniform distribution of Si3N4 particles in AA6063 matrix and its composition was confirmed by EDS analysis. As a result, the minimum wear rate was obtained for the composite contains 10 wt% Si3N4, load of 29.43 N, sliding distance of 1500 m and the sliding velocity of 3 m s−1. ANOVA result reveals that, the weight percentage of reinforcement has the higher percentage of contribution to influence the wear rate of the composite. The confirmation test was conducted and the results are well agreed with optimized parameters.

Optimization of wear parameters and their relative effects on stir cast AA6063-Si3N4 Composite

This study investigates the synthesis, characterization, and corrosion behavior of AA6063 composites with the inclusion of micron-sized titanium carbide (TiC) particles with different weight percentages. AA6063/TiC particulate composites containing 0, 3, 6, 9, and 12 weight percent of TiC particles were produced by stir casting. The homogeneous dispersion of TiC particles in the AA6063/TiC composites was revealed from the scanning electron microscopy analysis. Energy dispersive X-ray spectroscopy analysis was conducted to ensure the presence of reinforcement particles in the matrix. Mechanical and corrosion properties of the produced composites are evaluated. The addition of TiC particles to the AA6063, the mechanical, electrical, and corrosion properties are initially increased and then decreased. Mechanical and corrosion study shows that the presence of 9 wt% of TiC particles in the matrix improved mechanical properties than other combination of TiC with the matrix material.

Mechanical, electrical, and corrosion behavior of AA6063/TiC composites synthesized via stir casting route

Thermal augmentation in parabolic trough collector solar water heater using rings attached twisted tapes

The paper focused on the electrochemical machining behavior of AA6063 reinforced with various weight percentages of TiC particles fabricated using stir casting method. The experiments are conducted by using an ECM tester. The machining performance was investigated based on Taguchi L16 array. Maximum MRR is get for medium quantity of TiC strengthening and superior values of voltage and electrolyte concentration. Scratches in the worn surfaces were also analyzed using scanning electron microscopy.

S. Saravanan

Papers

Spherical activated-carbon nanoparticles derived from biomass green tea wastes for anode material of lithium-ion battery

Optimization of wear parameters and their relative effects on stir cast AA6063-Si3N4 Composite

Mechanical, electrical, and corrosion behavior of AA6063/TiC composites synthesized via stir casting route

Thermal augmentation in parabolic trough collector solar water heater using rings attached twisted tapes

Optimization of Process Parameters of Electrochemical Machining of TiC-Reinforced AA6063 Composites