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This research work describes the effect of dispersed titanium carbide (TiC) nanoparticles into nickel plating bath on Ni/TiC nanostructured composite layers obtained by electro-codeposition. The surface morphology of Ni/TiC nanostructured composite layers was characterized by scanning electron microscopy (SEM). The composition of coatings and the incorporation percentage of TiC nanoparticles into Ni matrix were studied and estimated by using energy dispersive X-ray analysis (EDX). X-ray diffractometer (XRD) has been applied in order to investigate the phase structure as well as the corresponding relative texture coefficients of the composite layers. The results show that the concentration of nano-TiC particles added in the nickel electrolyte affects the inclusion percentage of TiC into Ni/TiC nano strucured layers, as well as the corresponding morphology, relative texture coefficients and thickness indicating an increasing tendency with the increasing concentration of nano-TiC concentration. By increasing the amount of TiC nanoparticles in the electrolyte, their incorporation into nickel matrix also increases. The hybrid Ni/nano-TiC composite layers obtained revealed a higher roughness and higher hardness; therefore, these layers are promising superhydrophobic surfaces for special application and could be more resistant to wear than the pure Ni layers.

This first edition of Testing Tribocorrosion of Passivating Materials Supporting Research and Industrial Innovation: A Handbook treats in a clear, concise, and practical manner an important material degradation and protection matter. It is designed as a handbook and provides a well structured approach of the basics needed to investigate the tribocorrosion behavior of passivating materials, and to conduct in a correct way a laboratory investigation on it. It provides answers on practical and theoretical approaches of tribocorrosion phenomena to engineers and medical persons involved with material assemblies subjected to aggressive environmental and mechanical conditions. For academic researchers it is a pertinent tool assisting them in how they can perform a tribocorrosion investigation and obtain results that are correctly interpreted and can be exchanged. Different parts of the book are illustrated with practical examples. This handbook is truly an indispensable guide for every professional who comes into contact with the complex material degradation and protection processes that take place under combined corrosion and wear conditions. Fields of interest include: transportation (aeronautics, maritime, rail, automotive), medical implants (orthopaedics, dentistry), biochemistry, food production, energy production, and machining. The coordination of this handbook writing was done by Professor Jean-Pierre Celis (Katholieke Universiteit Leuven, Belgium) and Professor Pierre Ponthiaux (Ecole Centrale Paris, France) assisted by twelve European experts who contributed jointly to the nine chapters of this handbook. Main topics dealt with are tribocorrosion phenomena in medical and industrial sectors, depassivation and repassivation phenomena, impact on synergism in tribocorrosion, specific testing techniques, coupling tribology-to-corrosion, design of a testing protocol, and normalisation.

To prolong the lifetime of hydraulic cylinders, a wear-resistant low-friction surface is required. Until now, hard Cr coatings were the best materials for this. However, in recent years, there has been an increasing pressure on the manufacturing of hard Cr plating and plated products, because of environmental and health hazards. The replacement of these coatings by alternatives has not been highly successful yet, because it requires extensive component testing, which is costly and time-consuming and thus not appropriate for material development. For this reason, there is a high need to develop tribological methods that simulate hydraulic cylinders’ component-testing closely. In addition, these new methods should also provide additional information (e.g., friction evolution) that can assist in the further development and optimization of alternative coatings. Having the above in mind and building on an existing method from the American Society for Testing and Materials (ASTM G133), a new test method that allows users to test directly on hydraulic cylinders was developed. This method can provide a relative ranking of both the wear resistance and frictional performance of alternative coatings in direct comparison to state-of-the-art hard Cr. Importantly, the method is repeatable and has a much shorter test duration than full-scale component tests, thereby accelerating material development significantly.

The electrodeposition method was used to obtain nanostructured layers of Co/nano-CeO2 on 304L stainless steel, from a cobalt electrolyte in which different concentrations of CeO2 nanoparticles (0, 10, 20, and 30 g/L) were dispersed. The electrodeposition was performed at room temperature using three current densities (23, 48, and 72 mA cm−2), and the time was kept constant at 90 min. The influence of current densities and nanoparticle concentrations on the characteristics of the obtained nanostructured layers is also discussed. An X-ray diffractometer (XRD) was used to investigate the phase structure and cobalt crystallite size of the nanostructured layers, and a contact angle (sessile drop method) was used to assess the wettability of the electrodeposited layers. The roughness of the surfaces was also studied. The results show that the nanostructured layers became more hydrophilic with increasing nanoparticle concentration and increasing current density. In the case of pure cobalt deposits, an increase in the current density led to an increase in the size of the cobalt crystallites in the electrodeposited layer, while for the Co/nano-CeO2 nanostructured layers, the size of the crystallites decreased with increasing current density. This confirms the nanostructuring effect of nano-CeO2 electrocodeposited with cobalt.

In this paper, the results on the surface morphology, nanohardness and tribocorrosion properties of electrodeposited nanostructured Ni/TiC hybrid layers compared with pure Ni layers are presented. The Ni/nano-TiC hybrid layers were obtained by electro-codeposition of TiC nanoparticles (50 nm mean diameter) with nickel from a Watts type bath, on 316L stainless steel support. The combined fretting-corrosion performance was investigated using a reciprocating ball-on-disk tribometer coupled to an electrochemical cell in an electrolyte which simulates the primary water circuit of Pressurized Water Reactors (PWRs). Open circuit potential, as in situ electrochemical technique was performed before, during and after fretting tests in order to obtain information on the changes in surface conditions induced by fretting. The results clearly revealed enhanced nanohardness, improved tribocorrosion properties and reduced coefficients of friction for Ni/nano-TiC hybrid layers as compared to pure Ni layers. The much improved nanohardness and tribocorrosion behaviour can be attributed to the TiC nanoparticles reinforced into Ni matrix.

This article reports on the development of thin films of p - and n -type bismuth telluride compounds which are suitable for microelectromechanical systems (MEMS) thermoelectric energy harvesters. Films were prepared by the pulsed laser deposition technique. It is shown that the thin films of binary Bi-Te alloys outperformed considerably their ternary counterparts. Furthermore, the highest thermoelectric figure of merit ( ZT ) was found to be 0.39 for the p -type Bi 32 Te 68 alloy, whereas the optimal n -type alloy was Bi 25 Te 75 , which was characterized by a relatively low stress gradient.

This paper presents novel results on the effects of the dispersion of titanium carbide nanoparticles (50 nm mean diameter) into a nickel-plating electrolyte on the corrosion behavior of the nanocomposite layers obtained. The Ni/nano-TiC layers are compared with pure nickel layers obtained at the same electrodeposition parameters with 60 mA·cm−2 current density and 10 min deposition time. The comparative corrosion performances are investigated using a three-electrode electrochemical cell in a solution (mixed boric acid with lithium hydroxide), which simulates the primary water circuit of pressurized water reactors (PWRs). Open circuit potential measurement and electrochemical impedance spectroscopy were employed as the electrochemical methods, using an electrochemical workstation connected to an electrochemical cell, as well as a PC with software to drive the experimental work. The results clearly revealed enhanced corrosion properties for the Ni/nano-TiC hybrid layers as compared to the pure Ni layers. The significantly improved corrosion behavior can be attributed to the TiC nanoparticles embedded into the Ni matrix, which have the effect of insulating centers at the composite layer/corrosive solution interface.

This first edition of Testing Tribocorrosion of Passivating Materials Supporting Research and Industrial Innovation: A Handbook treats in a clear, concise, and practical manner an important material degradation and protection matter. It is designed as a handbook and provides a well structured approach of the basics needed to investigate the tribocorrosion behavior of passivating materials, and to conduct in a correct way a laboratory investigation on it. It provides answers on practical and theoretical approaches of tribocorrosion phenomena to engineers and medical persons involved with material assemblies subjected to aggressive environmental and mechanical conditions. For academic researchers it is a pertinent tool assisting them in how they can perform a tribocorrosion investigation and obtain results that are correctly interpreted and can be exchanged. Different parts of the book are illustrated with practical examples. This handbook is truly an indispensable guide for every professional who comes into contact with the complex material degradation and protection processes that take place under combined corrosion and wear conditions. Fields of interest include: transportation (aeronautics, maritime, rail, automotive), medical implants (orthopaedics, dentistry), biochemistry, food production, energy production, and machining. The coordination of this handbook writing was done by Professor Jean-Pierre Celis (Katholieke Universiteit Leuven, Belgium) and Professor Pierre Ponthiaux (Ecole Centrale Paris, France) assisted by twelve European experts who contributed jointly to the nine chapters of this handbook. Main topics dealt with are tribocorrosion phenomena in medical and industrial sectors, depassivation and repassivation phenomena, impact on synergism in tribocorrosion, specific testing techniques, coupling tribology-to-corrosion, design of a testing protocol, and normalisation.

The electrodeposition method was used to obtain nanostructured layers of Co/nano-CeO[sub.2] on 304L stainless steel, from a cobalt electrolyte in which different concentrations of CeO[sub.2] nanoparticles (0, 10, 20, and 30 g/L) were dispersed. The electrodeposition was performed at room temperature using three current densities (23, 48, and 72 mA cm[sup.−2] ), and the time was kept constant at 90 min. The influence of current densities and nanoparticle concentrations on the characteristics of the obtained nanostructured layers is also discussed. An X-ray diffractometer (XRD) was used to investigate the phase structure and cobalt crystallite size of the nanostructured layers, and a contact angle (sessile drop method) was used to assess the wettability of the electrodeposited layers. The roughness of the surfaces was also studied. The results show that the nanostructured layers became more hydrophilic with increasing nanoparticle concentration and increasing current density. In the case of pure cobalt deposits, an increase in the current density led to an increase in the size of the cobalt crystallites in the electrodeposited layer, while for the Co/nano-CeO[sub.2] nanostructured layers, the size of the crystallites decreased with increasing current density. This confirms the nanostructuring effect of nano-CeO[sub.2] electrocodeposited with cobalt.

To evaluate the wear patterns of orthodontic archwires in dry and wet conditions in-vitro.The patterns of wear of stainless steel and NiTi orthodontic archwires were investigated with a fretting wear tribometer fitted with an alumina ball. The tribometer was operated at 23°C in three different environments: ambient air with 50 per cent relative humidity (RH), 0.9 wt. per cent sodium chloride solution and deionised water. Differences in the wear characteristics of the archwires were investigated by scanning electron microscopy. Energy Dispersive X-ray Analysis and Inductively Coupled Plasma Analysis were used to investigate the surface composition of the wires, the wear debris generated during fretting and the corrosion products in the test solutions.Both archwire materials were degraded by oxidational wear in ambient air. The NiTi wires were more resistant to wear than the stainless steel wires. In the aqueous media the stainless steel wires were degraded by abrasive wear, while the NiTi wires were degraded by adhesive wear.In ambient air with 50 per cent RH, NiTi wires were more resistant to wear than stainless steel wires. Both archwire materials exhibited higher wear rates in the solutions than in air, indicating some synergism between the wear and corrosion processes. In the solutions the stainless steel archwires had a much lower corrosion-wear resistance than the NiTi archwires.