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Article
Publication date: 10 August 2015

Yuncai Zhao, Fei Yang and Yongming Guo

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

Abstract

Purpose

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

Design/methodology/approach

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.

Findings

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.

Originality/value

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.

Details

Industrial Lubrication and Tribology, vol. 67 no. 5
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 1 March 1987

Derek S.D. Norwood

In recent years aluminium has become a very widely used material in the construction industry. Light weight, good corrosion resistance and ease of fabrication lends itself…

Abstract

In recent years aluminium has become a very widely used material in the construction industry. Light weight, good corrosion resistance and ease of fabrication lends itself to a whole variety of end uses. Although the tendency for aluminium to oxidise in the atmosphere is itself a form of chemical “protection”, improvements in weather and chemical resistance can be gained from the use of a variety of surface coatings. These coating technologies are typically of the following types: polyvinylidine difluoride, water‐borne electro‐paint, conventional solvent‐based paints, powder coatings and anodising. The two most popular technologies in use today are: TGIC (Triglycidyl isocyanurate)/polyester powder coatings and polyvinylidine difluoride (PVDF) solvent‐based coatings. Coated aluminium has the added competition in the window frame and door frame market from uPVC. Only coated aluminium will be discussed in this paper.

Details

Pigment & Resin Technology, vol. 16 no. 3
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 1 April 1985

I.B. Goldman and A. Krajewski

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…

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.

Details

Circuit World, vol. 12 no. 1
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 1 February 1993

M.A. Paczkowski and S.T. Reddy

Over the past few years there has been increasing utilisation of higher density surface mounting on printed wiring boards. As components and pads decrease in size, the…

Abstract

Over the past few years there has been increasing utilisation of higher density surface mounting on printed wiring boards. As components and pads decrease in size, the topography of the solder mask relative to the conductors becomes an important solderability issue. There exists convincing evidence that thinner, more conformal solder mask geometries improve soldering yields of both stencilled and wave soldered surface mount components. In order to provide the solder mask coverage required for improved assembly performance, the authors critically compared several commercially available solder mask coating technologies. The coating methods were appraised according to both assembly and printed wiring board manufacturing criteria. Within this programme, seven liquid photoimageable solder masks were also evaluated. The materials were rated according to their final cured properties (electrical, mechanical, chemical performance), their manufacturability in the printed wiring board manufacturing process (maximum throughput, major defects, etc.) and their performance in assembly operations (soldering yields, propensity to ‘solder ball’ formation, white residues, scratches, etc.). The information obtained was used to choose a solder mask strategy which would not only improve assembly efficiency but also increase PWB manufacturing yields and flexibility.

Details

Soldering & Surface Mount Technology, vol. 5 no. 2
Type: Research Article
ISSN: 0954-0911

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Article
Publication date: 9 February 2015

Yuncai Zhao, Fei Yang and Yongming Guo

The purpose of this paper is to investigate the tribological properties of a textured lubricating wear-resistant coating modified by nano-SiC at a high temperature. Its…

Abstract

Purpose

The purpose of this paper is to investigate the tribological properties of a textured lubricating wear-resistant coating modified by nano-SiC at a high temperature. Its aim is to explore the influence of a new composite method on the organisation and structure of sprayed coatings as well as the evolution rules governing their high-temperature tribological properties.

Design/methodology/approach

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, using nano-SiC particles as a filler, the KF301/WS2 nano-modified coating with its round, pit-type texture was prepared by laser re-melting technology and a surface texturing technique. Two kinds of coating micro-organisations and structures were examined by scanning electron microscopy, and the tribological properties of both the modified and conventional coatings were studied at a high temperature.

Findings

Results showed that nano-particles could effectively improve the coating micro-structure, and make the structure denser and more uniform, thus significantly increasing the wear resistance of the coating. When the friction and wear processes were stable, the friction coefficient decreased by 13 per cent, while the wear loss decreased by 45.9 per cent.

Originality/value

This research concentrating on the study of the process and performance of coatings doped with nano-particles by laser re-melting incorporating simultaneous surface texturing, and studies of their high-temperature tribological properties. That is because applying nano-particle modification technology to the development of wear-resistant coatings, and by applying the nano-particles to such coatings by thermal spraying technology, they can achieve a modification of the coating which makes the structure denser and more uniform.

Details

Industrial Lubrication and Tribology, vol. 67 no. 1
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 14 September 2010

R.A. Mhatre, P.A. Mahanwar, V.V. Shertukde and V.A. Bambole

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…

Abstract

Purpose

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.

Design/methodology/approach

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.

Findings

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.

Research limitations/implications

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.

Practical implications

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

Originality/value

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

Details

Pigment & Resin Technology, vol. 39 no. 5
Type: Research Article
ISSN: 0369-9420

Keywords

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Article
Publication date: 15 October 2018

Jaroslaw Sienicki, Wojciech Zórawski, Adam Dworak, Piotr Koruba, Piotr Jurewicz and Jacek Reiner

The purpose of this paper is to propose cold spraying and laser cladding processes as alternatives to cadmium and chromium electroplating, respectively. There are many…

Abstract

Purpose

The purpose of this paper is to propose cold spraying and laser cladding processes as alternatives to cadmium and chromium electroplating, respectively. There are many substances or chemicals within the coating technology that can be identified as substances of very high concern because of their carcinogenic or mutagenic nature. Cadmium and chromium undoubtedly belong to these items and are the basic constituents of electrolytic coating processes. Finding an alternative and adapting to the existing restrictions of the usage of such hazardous products stands for many to be or not to be in the market.

Design/methodology/approach

The research work was focused on down selecting the appropriate materials, producing the coating samples, testing their properties and optimizing process parameters by statistical method. On the one hand, the high-pressure cold spray system and spraying of the titanium coating on the landing gear component, and on the other hand, the high-energy laser cladding facility and the wear resistant cobalt-based coating deposited onto the shock absorber piston. Substrates of these two applications were made of the same material, 4330 – high-strength low-carbon steel.

Findings

Meeting the requirements of Registration, Evaluation, Authorization and Restriction of Chemicals implies undertaking research and implementation work to identify alternative processes. The work provides the technical characteristics of new coatings justifying application readiness of the researched processes.

Originality/value

Taguchi’s design of experiment method was combined with the measurements and analysis of specified coating properties for the optimization of the cold spray process parameters. There is also laser cladding process development presented as a fast rate technology generating coatings with the unique properties.

Details

Aircraft Engineering and Aerospace Technology, vol. 91 no. 2
Type: Research Article
ISSN: 1748-8842

Keywords

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Article
Publication date: 1 September 1976

Americus

More articles have been published about powder coating in the last two years than about any other phase of the protective coatings industry. From this almost overwhelming…

Abstract

More articles have been published about powder coating in the last two years than about any other phase of the protective coatings industry. From this almost overwhelming flurry of print, certain factors emerge. The first is that powder coating technology is certainly a valid and useful one. It has established itself as an integral contributor to the achievements of the protective coatings industry and, without doubt, it will be with us for many years to come. Its success is due to its many advantageous factors which have been reviewed many times in the past. Great strides have been made in that a highly versatile group of powders are now available with both thermoset and thermoplastic properties; it is possible to achieve thin coatings; and the savings in terms of effective powder usage have been well‐documented. Where there is overspray, equipment has been evolved for recycling. Stressed most often has been powder coating's contribution to a non‐polluting painting operation. Powder coating, on the other hand, does not solve the energy shortage problem since the coatings must be fused and baked. However, less energy is required than for solvent based coatings simply because the energy requirements associated with solvent removal are eliminated.

Details

Pigment & Resin Technology, vol. 5 no. 9
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 4 July 2008

Abstract

Details

Pigment & Resin Technology, vol. 37 no. 4
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 1 April 2005

Harpreet Singh, D. Puri and S. Prakash

Plasma spray coating technologies are capable of depositing a wide range of compositions without significantly heating the substrate. The objective is to characterise…

Abstract

Purpose

Plasma spray coating technologies are capable of depositing a wide range of compositions without significantly heating the substrate. The objective is to characterise plasma sprayed metallic coatings on a Fe‐based superalloy.

Design/methodology/approach

NiCrAlY, Ni‐20Cr, Ni3Al and Stellite‐6 metallic coatings were deposited on a Fe‐based superalloy (32Ni‐21Cr‐0.3Al‐0.3Ti‐1.5Mn‐1.0Si‐0.1C‐Bal Fe) by the shrouded plasma spray process. The coatings were characterised in relation to coating thickness, porosity, microhardness and microstructure. The high temperature oxidation behaviour of the coatings was investigated in brief. The techniques used in the present investigation include metallography, XRD and SEM/EDAX.

Findings

All the coatings exhibited a lamellar structure with distinctive boundaries along with the presence of some porosity and oxide inclusions. The microhardness of the coatings was observed to vary with the distance from the coating‐substrate interface. The St‐6 coating had the maximum microhardness, whereas the lowest hardness was exhibited by the Ni3Al coating. The phases revealed by XRD of the coatings confirmed the formation of solid solutions, whereas EDAX analysis of the as‐sprayed coatings confirmed the presence of basic elements of the coating powders. So far as high temperature oxidation behaviour is concerned, all of the coatings followed the parabolic rate law and resulted in the formation of protective oxide scales on the substrate superalloy.

Originality/value

The plasma spray process provides the possibility of developing coatings of Ni3Al as well as commercial available NiCrAlY, Ni‐20Cr and St‐6 powders on Fe‐based superalloy Superfer 800H

Details

Anti-Corrosion Methods and Materials, vol. 52 no. 2
Type: Research Article
ISSN: 0003-5599

Keywords

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