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1 – 10 of over 17000He Chuang, Wang Fan, Liu Zhicheng and Kong Dejun
The purpose of this study is to investigate the effect of laser scanning speed (LSS) on the corrosive-tribological performance of Ni-60%WC coating in Wusu mine water, which was…
Abstract
Purpose
The purpose of this study is to investigate the effect of laser scanning speed (LSS) on the corrosive-tribological performance of Ni-60%WC coating in Wusu mine water, which was beneficial to improve the friction–wear performance of cylinder liner on water injection pump.
Design/methodology/approach
Ni-60%WC coatings were fabricated on 45 steel by laser cladding, and the microstructure and tribological performance was analyzed using a super depth of field microscope and ball-on-plate friction tester, and the wear mechanism was also discussed.
Findings
At room temperature (RT, 25 ± 2 °C), the average coefficients of friction of substrate and Ni-60%WC coatings fabricated at the LSS of 6, 10, 12 and 14 mm/s are 0.48 ± 0.08, 0.23 ± 0.01, 0.21 ± 0.05, 0.22 ± 0.02 and 0.25 ± 0.04, respectively, and the corresponding wear rates are 8.755 × 104, 4.525 × 103, 1.539 × 103, 1.957 × 103 and 2.743 × 103 µm3·s–1·N–1, respectively, showing that the coating fabricated at the LSS of 10 mm/s has best friction reduction and wear resistance. The wear mechanism of Ni-60%WC coating is abrasive wear, fatigue wear and oxidative wear, which is resulted from the WC particles with the high-hardness.
Originality/value
Ni-60%WC coatings were first applied for cylinder liner, and the effect of laser scanning speed on its tribological performance was investigated.
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Sun Chengwen, Li Wei and Kong Dejun
This paper aims to investigate the effect of Ti3SiC2 on the high-temperature tribological behaviors of NiCr coating, which was beneficial to improve the friction-wear performance…
Abstract
Purpose
This paper aims to investigate the effect of Ti3SiC2 on the high-temperature tribological behaviors of NiCr coating, which was beneficial to improve the friction-wear performance of hot work mold.
Design/methodology/approach
NiCr-Ti3SiC2 coatings were prepared on H13 steel substrate by laser cladding. The microstructure, phases and hardness of obtained coatings were analyzed using a super-depth of field microscope, X-ray diffraction and microhardness tester, respectively, and the tribological performance of obtained coatings at 500°C was investigated using a high-temperature tester.
Findings
The results show the NiCr-Ti3SiC2 coatings are comprised of γ-Ni solid, solution, TixNiy, TiC and Ti3SiC2 phases, and the coating hardness is increased with the increase of Ti3SiC2 mass fraction, which is contributed to the fine-grain and dispersion strengthening effect by the addition of Ti3SiC2. The NiCr-Ti3SiC2 coatings present excellent friction reduction and wear resistance by the synergetic action of Ti3SiC2 lubricant and hard phase, and the wear mechanism is predominated by abrasive wear and oxidation wear.
Originality/value
Ti3SiC2 phase was used to reinforce the tribological performance of H13 steel at high temperature, and the roles of friction reduction and wear resistance were discussed.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-01-2023-0004/
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Zhishi Li, Huajin Wang, Sheng Zhang, Wei Zhao, Qinghuai Jiang, Mingqiang Wang, Jun Zhao and Wei Lu
– This paper aims to discuss how acrylic resin influences the smoke generation of intumescent flame retardant coatings.
Abstract
Purpose
This paper aims to discuss how acrylic resin influences the smoke generation of intumescent flame retardant coatings.
Design/methodology/approach
Thermal decomposition kinetics is used in this study to simulate the burning process. The thermal decomposition of acrylic resin can be identified in the intumescent coatings through the multi-peak fitting of derivative thermogravimetric (DTG) curves. The dormant influence of acrylic resin, combined with the smoke density, is calculated.
Findings
Multiple peaks fitting method of DTG curves helps estimate the decomposition process of acrylic resin in flame retardant coating. Combining DTG data with the smoking curve, smoking generation of acrylic resin during the combustion could be evaluated. The decomposition conversion rate of acrylic resin is 21.13 per cent. Acrylic resin generates 34.64 per cent of the total amount of smoke produced during the combustion of intumescent flame retardant coatings.
Research limitations/implications
All the other intumescent flame retardant coating systems could be studied using the same approach as that used in this work to achieve an improved understanding of the smoke generation process during combustion.
Practical implications
The method developed here provided a simple and practical solution to analyse the decomposition and smoking generation of acrylic resin in the coating mixtures. It also can be used to analyse any thermal decomposition process of any mixed compounds.
Originality/value
The analysis method to evaluate resin’s smoking generation of coating’s total generation is novel, and it could be applied in all kinds of coatings and mixtures to estimate the smoking generation of one composition.
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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.
Abstract
Purpose
The purpose of this work was to study the effect of different wood surface preparations on the wetting and adhesion of coating.
Design/methodology/approach
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.
Findings
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.
Research limitations/implications
Chemical modifications of wood surfaces affected the wetting of various coatings.
Practical implications
Various surface properties could be changed using preparation that affects important coating properties.
Social implications
Unfortunately, the properties of transparent wood coatings used outdoors disappear through the early years of use, essentially due to the wood substrate’s photodegradation.
Originality/value
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.
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Introduction It is well appreciated that the primary purpose of an external coating on a pipeline is of course to prevent corrosion and the coating system should possess…
Abstract
Introduction It is well appreciated that the primary purpose of an external coating on a pipeline is of course to prevent corrosion and the coating system should possess appropriate physical and chemical properties which allow this function to be fulfilled. There are, however, additional mechanical requirements of a coating system if the material is to be effective during handling, construction, testing and operation and it is within the context of these latter requirements that current interest in external coatings has arisen.
P.K. Sahu, P.A. Mahanwar and V.A. Bambole
The purpose of this paper is to prepare heat insulating exterior emulsion coating and to study its heat insulating property along with mechanical, chemical and weathering…
Abstract
Purpose
The purpose of this paper is to prepare heat insulating exterior emulsion coating and to study its heat insulating property along with mechanical, chemical and weathering resistance properties with varying amount of hollow glass microspheres and cenospheres.
Design/methodology/approach
For heat insulating effect, various compositions were made by incorporating different proportions of hollow glass microspheres (HGM) and cenospheres (C). The mechanical, chemical, morphological and optical properties of the coating films were studied and compared.
Findings
Addition of hollow glass microspheres and cenospheres enhanced heat insulating property of the coating, hardness, tensile strength and wet scrub resistance. It was evaluated that optimum loading for both cenospheres and hollow glass microspheres was 10 wt.% and both the systems showed good mechanical, chemical resistance and weathering properties.
Practical implications
Addition of hollow glass microspheres and cenospheres to acrylic emulsion coating is a simple and inexpensive method.
Originality/value
The new heat insulating coatings with good thermal insulation properties and improved weather resistance were prepared. These coatings could find applications in demanding fields such as exterior wall coatings and roof coatings.
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Modern powder coatings were introduced in 1952. They created great interest and much was written about them and much predicted for them. They did indeed find a niche, but they did…
Abstract
Modern powder coatings were introduced in 1952. They created great interest and much was written about them and much predicted for them. They did indeed find a niche, but they did not deliver quite as had been anticipated and by the early 1960's their star was waning. But one must never discount the impact of advancing technology — particularly when economy, convenience and performance are involved. Novel methods of application, primarily electrostatic spraying to complement the original fluidised bed approach, new formulations, faster curing epoxies and a better understanding of both the virtues and the defects of this method for industrial coating, has brought powder coatings back into their own.
Introduction Surface coatings of metal are applied chiefly to iron and steel, but sometimes also to non‐ferrous alloys, in order to improve the appearance or to increase corrosion…
Abstract
Introduction Surface coatings of metal are applied chiefly to iron and steel, but sometimes also to non‐ferrous alloys, in order to improve the appearance or to increase corrosion resistance. Increased corrosion resistance may be obtained in either of two ways: (1) a more protective or noble metal is applied, or (2) a less noble or sacrificial coat is formed.
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…
Abstract
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.
Qingjun Ding and Gai Zhao
The purpose of this paper is to study the mechanism and effect of rare earth oxides on the properties of Cr2O3-TiO2 coating.
Abstract
Purpose
The purpose of this paper is to study the mechanism and effect of rare earth oxides on the properties of Cr2O3-TiO2 coating.
Design/methodology/approach
Cr2O3-TiO2 coatings with different proportion of CeO2 were deposited by atmospheric plasma spraying on aluminum alloy 7005. The mechanical, microstructure and tribological properties were studied.
Findings
The addition of CeO2 could improve the micro-hardness; decrease porosity, wear rate and surface roughness of the coating; and increase the bonding strength between the coating and substrate. The wear mechanism is a mixture of abrasive and adhesive wear.
Originality/value
The addition of CeO2 could refine microstructure, and promote the formation of solid solution structure, and then affect the properties of coatings.
Details