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The effect of cryogenic heat treatment on the mechanical properties of different materials has been frequently investigated by researchers in recent years. The purpose of this paper is to investigate wear behaviour of monolayer, multilayer and nanocomposite coatings after cryogenic heat treatment. It is a first in its field in terms of both the heat treatment used and the coatings examined.

The aCN/TiAlN, TiAlN and ncTiAlSiN hard coatings deposited on the AISI D2 steel substrate were subjected to cryogenic heat treatment at −145^oC and −196^oC for 24 h and then tempered at 200^oC for 2 h. Then, the samples were subjected to wear tests of 5, 10 and 15 N three different load values. The wear mechanisms occurring on the wear surfaces were determined by scanning electron microscope supported by EDS.

Oxidation, fatigue and delamination wear mechanisms were realized on the surfaces of the samples subjected to dry sliding wear test. The wear resistance of S1 increased with cryogenic heat treatment. According to the wear test results of the untreated samples, it was found that the samples with lower hardness than the others had higher wear resistance. The wear resistance of S1 and S2 samples was increased by cryogenic heat treatment. The best wear resistance in all parameters was obtained by S1. Oxidation in the S1 was found to have a positive effect on wear resistance. According to EDS results after wear of S2, chromium-rich layer was found on the surface of the material. It is understood that cryogenic heat treatment causes carbide precipitation in the inner structure of the substrate material.

The effect of cryogenic heat treatment on the mechanical properties of different materials has been frequently investigated by researchers in recent years. In this study, wear behaviour of monolayer, multilayer and nanocomposite coatings after cryogenic heat treatment was investigated. It is a first in its field in terms of both the heat treatment used and the coatings examined.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-03-2020-0111/

The paper's aim is to synthesise ultraviolet (UV) curable polyurethane acrylate based on polyester polyol and to study change in its mechanical, chemical, optical and weather resistance properties with varying amount of nanosilica. It also seeks to determine its optimum loading levels for property maximisation.

New UV curable polyurethane acrylate has been synthesised using polyester polyol, blend of isophorone diisocyanate and toluene diisocyanate and hydroxyl ethyl acrylate. This resin was incorporated with nanosilica (1‐3 per cent) on the basis of total solids. The newly synthesised material was characterised by fourier transform infrared spectroscopy, gel permeation chromatography, X‐ray diffraction and scanning electron microscopy. The mechanical, chemical and optical properties of the coating films were studied and compared.

The hardness, tensile strength and abrasion resistance show significant enhancement with increasing amount of nanosilica. It is also found that UV cured polyurethane acrylate nanocoating exhibited improved weather resistance. The optimum concentration of nanosilica for better performance is found to be 3 per cent of total solids. The improvement is the result of inherent nature of nanosilica.

Nanosilica used in present context is having 10 nm mean diameter and near about 600 m²/g surface area. Nanosilica having different particle size, surface area and surface modification can be used to improve more specific properties.

Addition of nanosilica particles to polyurethane acrylate coating is a simple and inexpensive method resulting in phenomenal increase in properties.

The new organic‐inorganic hybrid nanocoating with improved weather resistance was synthesised. These coatings could find applications in demanding fields such as automotive topcoats.

The purpose of this paper is to examine the effect of substrate temperature on friction coefficient and surface roughness of titanium nitride (TiN) coatings deposited on high‐speed steel (HSS) using commercially available cathodic arc evaporation physical vapour deposition system.

The goal of this work is to determine the usefulness of TiN coatings in order to improve the friction coefficient and surface roughness of HSS verses substrate temperature, as vastly used in cutting tool industry and many others. A Pin‐on‐Disc test was carried out to study the coefficient of friction verses sliding distance. Surface roughness of deposited coatings was studied via surface roughness tester and atomic force microscope (AFM).

Friction coefficient increased at higher temperature as compared to the coating deposited at lower substrate temperature. Surface roughness measured via both instruments showed similar trend in recorded data and, i.e. increased by increasing substrate temperature. AFM study showed that bearing ratio (per cent) decreased, whereas, fractal dimension increased with an increase in substrate temperature.

It is implied that choosing a substrate temperature above 450°C in the existing coating system could damage some machine parts.

This scenario develops an approach to optimize the coating properties verses substrate temperature for specific application, such as cutting tools for automobiles and aircrafts.

The coating deposited at lower temperature showed better friction coefficient and surface roughness than the coating deposited at higher temperature and vice versa.

This paper aims to investigate the structural, tribological and electrochemical properties of Ag₂O, ZnO, NiO coatings and Ag₂O/ZnO/NiO nanocomposite films deposited on commercially pure titanium.

Ceramic thin films (Ag₂O, ZnO, NiO coatings and Ag₂O/ZnO/NiO nanocomposite film) were deposited on commercially pure titanium (CP-Ti) substrate. Surface characterization of the uncoated and coated samples was made by structural surveys (scanning electron microscopic examinations and X-ray diffraction analyses), hardness measurements, tribological and corrosion experiments.

Results were indicated that sol-gel coatings improved the wear and corrosion resistance of CP-Ti, and the best results were seen at the nanocomposite coating. It may be attributed to its small grain size, high surface hardness and high film thickness.

This study can be a practical reference and offers insight into the influence of nanocomposite ceramic films on the increase of hardness, tribological and corrosion performance. Also, the paper displayed a promising approach to produce Ag₂O/ZnO/NiO nanocomposite coating on commercially pure titanium implants for biomedical applications.

This paper aims to study the effect of SiO₂ nano‐particulates on the corrosion behaviour of Ni‐W/SiO₂ nanocomposite coatings.

Weight loss measurements, electrochemical measurements and scanning electron microscope were used to study the corrosion behaviour of Ni‐W/SiO₂ nanocomposite coatings in NaCl solution.

The incorporation of SiO₂ nano‐particulates into the Ni‐W alloy matrix significantly increased the corrosion resistance. The improvement in corrosion resistance was due to the SiO₂ nano‐particulates acting as physical barriers to the corrosion process by filling in crevices, gaps and microscopic holes on the surface of the Ni‐W alloy.

This study highlights the use of nano‐particulates for the control of Ni‐W alloy coating corrosion and opens a new route for industry in the anti‐corrosion field.

SiO₂ and SiO₂-ZrO₂ nanocomposites were coated by sol–gel dipping method on carbon steel 178 (178 CS). Nanostructure and phase properties of nanocomposite coating were characterized using X-ray diffraction, scanning electron microscopy and Fourier transform infrared studies. Electrochemical polarization and electrochemical impedance spectroscopy (EIS) tests were used to study the corrosion behavior of 178 CS that was coated with SiO₂-ZrO₂ nanocomposite and SiO₂ coating in 3.5 per cent NaCl solution. The results indicated that SiO₂-ZrO₂ nanocomposite coating performed better in terms of corrosion resistance compared with SiO₂ coating. The corrosion resistance of SiO₂-ZrO₂ nanocomposite coating could be increased significantly in by approximately three and seven times of that of SiO₂ coating and bare 178 CS, respectively.

SiO₂ and SiO₂-ZrO₂ nanocomposites were coated using sol–gel dipping method on carbon steel 178. Electrochemical polarization and EIS tests have been used to study the corrosion behavior of 178 CS that was coated with SiO₂-ZrO₂ nanocomposite and SiO₂ coating in 3.5 per cent NaCl solution.

Results indicated that SiO₂-ZrO₂ nanocomposite coating performed better in terms of corrosion resistance compared with SiO₂ coating. The corrosion resistance of SiO₂-ZrO₂ nanocomposite coating could be increased significantly in by approximately three and seven times of that of SiO₂ coating and bare 178 CS, respectively.

The SiO₂-ZrO₂ nanocomposite coating film showed significant improvement in corrosion resistance of 178 CS. The highest polarization resistance of the nanocomposite coating film was 10,600 Ω/cm² from SiO₂-0.2 ZrO₂.

The main aim of this study was to improve current efficiency and to obtain thicker coatings via aluminum oxide (Al₂O₃) addition to the chromium (Cr) (III) bath.

Pure Cr and nanocomposite Cr–Al₂O₃ coatings were electrodeposited from Cr (III) bath onto cathode copper substrates by conventional method. Dependence of current efficiency to current density, Al₂O₃ content and particle size were investigated.

Current efficiency increased with Al₂O₃ amount and decreased with Al₂O₃ particle size. Maximum current efficiency was achieved at 25 A/dm₂ for pure Cr and 30 A/dm₂ for composite coatings. Al₂O₃ bath content, current density and stirring rate increased the coating Al₂O₃ weight per cent significantly. Addition of Al3+ bath composition inhibited nanoparticle agglomeration, increasing film homogeneity. Cr–Al₂O₃ nanocomposites showed higher microhardness and better corrosion resistance than pure Cr layer.

Cr (III) is not as toxic and as carcinogenic as Cr (VI) which is widely used for Cr electroplating these days. Low current efficiency and poor product quality are, however, major drawbacks of the former. This paper describes significant improvements obtainable by addition of Al₂O₃ nanoparticles to the Cr (III) bath for increasing the microhardness, the corrosion resistance and the current efficiency of the deposition.

The purpose of this paper is to investigate the effect of TiO₂ nanoparticle content on the corrosion behavior of Ni‐Cr/TiO₂ nanocomposite coatings applied by pulse‐reverse electroplating.

Ni‐Cr/TiO₂ nanocomposite coatings with various contents of TiO₂ nanoparticles were electrodeposited by pulse‐reverse method from a bath containing TiO₂ nanoparticles to be codeposited and citric acid as the complexing agent. The surface morphology and the composition of coatings were studied by scanning electron microscopy (SEM) equipped by energy dispersive X‐ray system (EDS). The corrosion performance of coatings in the 0.5 M NaCl as a corrosive solution was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) methods.

It was found that the surface of Ni‐Cr/TiO₂ nanocomposite coatings showed a finer structure that was more uniform and compact in appearance than was that of Ni‐Cr coatings. The incorporation of TiO₂ nanoparticles in the alloy coating matrix improved the corrosion performance of the coatings and the higher content of nanoparticles gave better corrosion resistance.

Applying the Ni‐Cr coatings by the pulse‐reverse plating method eliminated cracks that were a problem in the Ni‐Cr alloy coating structure. Furthermore, the corrosion resistance was improved by the addition of TiO₂ nanoparticles to the alloy matrix. This paper reports the optimum plating conditions that gave the better corrosion performance.

The purpose of the research was as follows. In situ modified urea formaldehyde resins were prepared from clay (montmorillonite) and organoclay in the presence of base catalyst. Different clay contents (1 wt%, 3 wt%, 6 wt%) were used to produce clay modified nanocomposite resins. These nanocomposites were characterized with FT‐IR, XRD as structural analysis and DSC as thermal analysis and their hardness was evaluated as mechanical analysis. The thermal results was compatible with hardness measurements and showed that using clay/organoclay added resin as a surface coating material provides significant improvement.

During synthesis of the resin, modification was carried out using urea/formaldehyde with molar ratio of 1/1.6, under basic medium with pH=10 and with temperature of 70°C by loading pristine and organomodified layered silicates.

X‐ray diffraction (XRD) results indicate that the interlayer space of pristine clay was increased significantly by one step, seeing that one step processes are crucial for industrial applications.

The reaction mixture must be stirred continuously. Temperature should be controlled in order to prevent the thermal curing of urea formaldehyde resin.

This study provides technical information for the synthesis of nanocomposite resins. The clay or organoclay modified resins may also promote the adhesive strength of coating and also inhibit corrosion effects to metal surfaces of the coated area.

This resin will be used for the coating material.

As T_g‐T_m region of some nanocomposites is enhanced, and by assessing the results of hardness measurements, it is concluded that these samples have further improved mechanical properties as a coating material than urea formaldehyde resin has.

The purpose of this study is to reveal the effect of nano-Al₂O₃ particle addition on the nucleation/growth kinetics, microhardness, wear resistance and corrosion resistance of Co–P–xAl₂O₃ nanocomposite plating.

The kinetics and properties of Co–P–xAl₂O₃ nanocomposite plating prepared by electroplating were investigated by electrochemical measurements, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Vickers microhardness measurement, SRV5 friction and wear tester and atomic force microscopy.

A 12 g/L nano-Al₂O₃ addition in the plating solution can transform the nucleation/growth kinetics of the plating from the 3D progressive model to the 3D instantaneous model. The microhardness of the plating increased with the increase of nano-Al₂O₃ content in plating. The wear resistance of the plating did not adhere strictly to Archard’s law. An even and denser corrosion product film was generated due to the finer grains, with a high corrosion resistance.

The effect of different nano-Al₂O₃ addition on the nucleation/growth kinetics and properties of Co–P–xAl₂O₃ nanocomposite plating was investigated, and an anticorrosion mechanism of Co–P–xAl₂O₃ nanocomposite plating was proposed.