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The purpose of this work was to study the effect of different wood surface preparations on the wetting and adhesion of coating.

In this research, six different chemical preparations to evaluate the photostability and properties of wood coating. Also, the effect of the same wood treatments on the properties of the coating, i.e. wetting, adhesion and the permeability of two types of coatings, was investigated.

As a result, benzoyl chloride and chromic acid were found to be the most effective photostabilizing preparations. Solvent-based polyurethane was more compatible with the prepared wood surfaces compared with water-based alkyd coatings.

Chemical modifications of wood surfaces affected the wetting of various coatings.

Various surface properties could be changed using preparation that affects important coating properties.

Unfortunately, the properties of transparent wood coatings used outdoors disappear through the early years of use, essentially due to the wood substrate’s photodegradation.

Wood is a widespread substrate because of its comfortable handling, availability, proper cost of preparation and its good mechanical strength because of its density. Architects and designers tend to use wood in the construction of green buildings. However, this material is disposed to weathering while using outdoors and it should be solved.

The use of U‐V technology in conformal coating applications has come of age. This paper discusses the material, process, and equipment which recently have been utilised for the conformal coating of printed wiring boards. First is presented a description of the coating material properties, both uncured and in the cured state. Next follows a discussion of the processing scheme, parameters such as time, speed, and U‐V light source requirement. Hardware to enable the coating operation to fit into an automated assembly line is also described. Of special interest will be the employment of masking techniques to prevent coating of certain critical areas. Lastly, typical performance data on the actual product having the U‐V coating are presented. An overall appraisal of the entire U‐V system is included.

The key purpose of this study was to investigate the effects of different ultrasonic irradiation times on the wettability and other properties of the resulting water-based coating. The subject water-based coating was prepared using water-soluble polyester and amino resins by ultrasonic oscillation.

The coating was prepared by polymerising polyester and amino resins in water using ultrasonic oscillation. The coating was baked for 40 seconds at 350°C to coalesce and solidify the film. The contact angle, thermal stability and mechanical properties of the film, as well as the molecular weight (MW) and structure of the polyester resin, were determined.

The contact angle of the coating was found to decrease with ultrasonic irradiation; the mechanical properties and thermal stability were not altered when the irradiation time was longer than 5 hours. The MW of the polyester initially decreased then increased and stabilized with ultrasonic irradiation. The structure of polyester molecule and aggregated state of the solidified coating were not changed by ultrasonic irradiation.

In the study reported here, the effects of different ultrasonic irradiation times were investigated. Results of this research could benefit in-depth understanding of the influence of ultrasonic treatment on polyester resins and polyester coatings and could further promote the development of water-based coatings.

The contact angle of the water-based coating decreased by mechanical means. The effects of ultrasound on microstructure and properties of the coating and resin were discussed in detail.

This paper aims to discuss about the benefits of Cu(NO₃)₂ applied in coating paint film that consists of plant extract from Cassia Alata. Cu(NO₃)₂ has been added to the coating paint film as a colour stabilizer and as an antifungal property by forming a zone of inhibition towards fungal growth.

The coating paint film resin consists of a mixture of poly (methyl methacrylate) (PMMA) and acrylic polyol. The coating paint film’s performances were observed in terms of visible optical and physical appearance.

When exposed to the fungus Trichoderma Sp., a zone of inhibition of 208 mm² was formed around the coating paint film and therefore it gave the coating paint films an antifungal property. The commission internationale de l’éclairage (CIE) L*a*b* colour coordinate system was used to identify the colour changes in the coating paint film and it was found that the addition of Cu(NO₃)₂ to the coating paint film has a better colour stability, as it has a lower standard deviation (STD) value of 6.46 than the pure dye coating paint film of 8.95. The gloss of coating paint film with the addition of Cu(NO₃)₂ was found to be have a more stable gloss based on its smaller STD value at both angles taken at 20° and 60°.

The Cassia Alata plant has different amount of antifungal properties based on location its growth.

The coating paint film developed in this study is suitable for indoor applications.

The plant extract from the Cassia Alata gives the coating paint film an antifungal property.

To examine the mechanical properties of TiN PVD coated Ti‐6Al‐4V alloy through three‐point bending tests.

Ti‐6Al‐4V alloy is cut in size and polished and cleaned chemically before TiN PVD coating process. INSTRON three‐point bending equipment is used to conduct the bending tests for TiN coated and uncoated workpieces. During the tests, the load and displacement characteristics were recorded. The tests were terminated when the coating failed. Micrographs of surface and crack sites were obtained by SEM.

Coating failure occurs due to shearing effect on the tensile surface. The spalling and buckling of the coating on the compressive surface are observed. The compressive stress generated on the top surface (where the indent is in contact) did not cause adhesive failure of the coating. Moreover, cohesive cracks occur on the tensile surface of the coating. The crack ledge under the action of shear stress appears on the tensile surface of TiN coating and multi cracking of coating is resulted. The crack spacing is small indicating sliding and splitting separation between the adjacent columns in the coating.

The tests can be extended to include the duplex treated workpieces such as the heat treatment of surface prior to TiN coating. This enhances the interface properties of the coating and base alloy.

The results can be used to assess the TiN coating applications in cutting tools, particularly drill bits and punches.

This paper provides information on mechanical behavior of TiN coating when subjected to bending force and offers practical help for the researchers and scientists working in the coating area.

The purpose of this paper is to investigate the corrosion resistance of high velocity oxy-fuel (HVOF)-sprayed Diamalloy 2002 coating on carbon steel. The coating microstructure is examined in line with the corrosion resistance.

HVOF spraying of coating is achieved, and the coating response to electrolytic solution is measured experimentally in terms of corrosion resistance.

HVOF coating improves the corrosion resistance of the substrate such that the corrosion rate of the substrate is 7.1 mpy and the coating results in 4.5 mpy. However, presence of deep pit sites at the surface suggests the occurrence of preferential corrosion around the splat boundaries. In addition, closely spaced surface texture peaks act as crevice corrosion centers at the surface while initiating the formation of deep pit sites.

This study is limited by experimental investigations. In future, it may be extended to include model studies.

The findings of this study are very useful for those working in the coating industry. However, HVOF coating is limited to high temperature protection in harsh environments.

It is useful for the power industry, particularly for gas turbines.

It is an original work and describes the corrosion resistance of the coating surface. It is found that the coating improved the corrosion resistance of the steel surface.

The purpose of this paper is to investigate the influence of composite coating structure on the reliability of adhesive flip chip joints. The need for conformal coating is considered, especially for medical applications, and medical sterilization is also considered.

Two test lots were assembled and one of them was sterilized using gamma sterilization. Both test lots were coated first with epoxy and then with Parylene C, resulting in a composite coating structure. The reliability was studied using a constant humidity test and the failure analysis was performed with cross‐sections and scanning electron microscopy analysis. These results were compared to earlier research results on conformal coatings.

The reliability of both test lots proved to be good. The composite coating structure shields the joints from humidity and improves the reliability compared to non‐coated test samples. When the conformal coating was compared to the pure Parylene C coated test lot, the reliability was almost the same. This leads to the conclusion that the epoxy layer in the composite coating structure has no value when long‐term reliability is considered. Gamma sterilization does not greatly affect reliability. The epoxy coating under the Parylene C layer cracked during reliability testing.

The paper shows the influence of composite coating structure on the reliability of adhesive flip chip joints, particularly important in medical applications.

To examine the tensile properties of high velocity oxy‐fuel (HVOF) sprayed Inconel 625 coating of steel substrate before and after the aqueous corrosion.

Workpieces were cut from steel sheets. After chemical and ultrasonic cleaning, workpiece surfaces were sand blasted and HVOF sprayed Inconel 625 coated. The coated and un‐coated surfaces were subjected to the aqueous corrosion tests for one and three weeks. After the completion of the corrosion tests, tensile properties of the workpieces were examined.

The workpieces subjected to a three weeks static corrosion environment fail at a lower load than the untreated workpiece due to high stiffness. The defect sites in the coating and at the interface act as stress risers and contribute substantially crack initiation and propagation in the coating. Under increasing tensile load in the plastic region, the substrate material can no longer support the coating. This results in extended cracking and gradually spalling of the coat. When the local critical stress for crack propagation is reached, elongated cracks occur, which in turn initiates splitting separation between the adjacent zones in the coating. The shear deformation of the adjusted zones results in the total failures of the coating.

The tests can be extended to include the duplex treated workpieces such as the laser treatment of surface after HVOF sprayed coating. This enhances the bonding of the coating through thermal integration of the coating and the base substrate material.

The results can be used to assess the HVOF sprayed coatings.

This paper provides information on mechanical behavior of HVOF sprayed coating when subjected to the tensile force and offers practical help for the researchers and scientists working in the coating area.

This paper seeks to examine the fatigue properties of HVOF sprayed Inconel‐625 coating of steel substrate before and after the aqueous corrosion.

Workpieces were cut from steel sheets. After chemical and ultrasonic cleaning, workpiece surfaces were sand‐blasted and HVOF sprayed Inconel‐625 coated. The coated and un‐coated surfaces were subjected to the aqueous corrosion tests for one and three weeks. After the completion of the corrosion tests, fatigue properties of the workpieces were examined.

Stainless steel coated workpieces demonstrated excellent fatigue life resistance versus coated carbon steel workpieces. Stainless steel workpieces apparently have a high‐cycle fatigue represented by in excess of 1.50 million cycles without cracking, thereby assuring a high‐fatigue life. The carbon steel specimens have low‐cycle fatigue and consequently a short fatigue life. In addition, high velocity impacting of splats on to the workpiece enhances the hardness of the surface. This, in turn, improves fatigue properties at the interface, particularly for stainless steel workpieces.

The tests can be extended to include the duplex treated workpieces such as the laser treatment of surface after HVOF sprayed coating. This enhances the bonding of the coating through thermal integration of the coating and the base substrate material.

The results can be used to assess the HVOF sprayed coatings.

This paper provides information on the fatigue behavior of HVOF sprayed coatings when subjected to the cyclic load and offers practical help for the researchers and scientists working in the coatings area.

The purpose of this paper is to investigate the effects of parallel texturing coating on antifriction mechanism of lubricating wear-resistant coating.

A KF301/WS2 lubricating wear-resisting coating was prepared on matrix material GCr15 by applying supersonic plasma spraying technology. On the basis of this sample, the KF301/WS2 modified coating with parallel pit-type texture was prepared by laser re-melting technology and a surface texturing technique. Their friction and wear behaviors were evaluated under ambient temperature, and the antifriction mechanism of two kinds of coatings were discussed.

Results showed that parallel texture has a certain impact on the tribological properties of the coating. When friction and wear reach stable state, the value of the friction coefficient of conventional coating was 0.115, while that of parallel texturing coating was 0.09, the latter decreased by 21 per cent. When the friction and wear time was up to 4 hours, the wear loss of the conventional coating was 0.29 mg, while that of the parallel texturing coating was 0.13 mg, the latter decreased by 55 per cent.

The tribological properties of parallel texturing coating were higher than conventional coating. That is because the change of three-body layer reduces the friction coefficient and the abrasive particles were collected by parallel texture, reducing the effects of debris.