Abrasive wear behaviour of thermal spray coatings (original) (raw)
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Modern Proficiency in Thermal Spray Coatings to Enhance Wear Resistance of Material
Various techniques are employed to protect the material from degradation. As the wear is a surface phenomenon and occurs mostly at outer surfaces. Most industry segments, significant financial losses may be incurred due to accelerated wear of various components. In order to minimize the effects of mechanical wear and extend product life, thermal spray coating solutions introduced into production and is further developing them to meet even more demanding wear applications. Therefore it is more appropriate and economical to use surface engineering for making surface modifications. High-velocity oxy-fuel (HVOF) is one of the thermal spraying techniques known for providing hard, wear resistant and dense micro structured coatings. Applying coatings using thermal spray is an established industrial method for resurfacing metal parts. The process is characterized by simultaneously melting and transporting sprayed materials, usually metal or ceramics, onto parts. Now a day's High-velocity oxy-fuel (HVOF) spray coatings are gaining popularity due to exceptional hardness, wear resistance and cost effectiveness. In this paper some studies on Thermal sprayed wear resistant coatings have been reviewed.
Abrasive wear behaviour of powder flame sprayed coatings on steel substrates
Materials & Design, 2002
The main purpose of thermal spraying method is to produce wear resistant surfaces. Easy applicability, very low possibility of metallurgical changes and low distortion of coated parts due to low heat transfer to the substrate and salvation of worn parts are some of the practical advantages of this process. In this study, abrasive wear behaviour of powder flame sprayed coatings on steel substrates has been investigated. Coating was carried out onto both hot and cold substrates by using four types of powders. Prior to the wear tests, the coated specimens were machined on a lathe and surface roughness and hardness measurements were carried out on the machined surfaces. Heating the substrates prior to the coating led to the decrease in the hardness of the coating layers. Abrasive wear resistance of flame sprayed coatings was seen to be dependent on the chemical composition and characteristics of coating materials and coating condition.
Welding Technology Review
In this article results of tribological and structural properties comparison of flame sprayed, by SupJet-S-Eutalloy® multipurpose system, two self-fluxing alloys of Ni-B-Si type in the form of powder for spraying with remelting are presented. Layers were produced on EN-GJL-250 grade grey cast iron with flake graphite in an austenitic matrix. Abrasive wear resistance examination acc. to ASTM G65-00 and erosive wear resistance examination acc. to ASTM G76-2 were performed. Obtained results were compared with abrasion-resistant steel Hardox® 400. Macro- and microscopic examination were carried enabling layer quality evaluation and structure of examined layer and base material determination. X-ray microanalysis was performed to obtain qualitative and quantitative data about microareas chemical composition. The Eutalloy® BronzoChrom 10185 powder flame sprayed layer with higher Boron and Silicon content was characterized by 13% lower wear intensity under mineral abrasive conditions and ab...
Abrasion-Corrosion of Thermal Spray Coatings
Thermal Sprayed Coatings and their Tribological Performances, 2015
WC-based thermal-spray and High Velocity Oxy-Fuel (HVOF) coatings are extensively used in a wide range of applications ranging from downhole drilling tools to gas turbine engines. WC-based thermal spray coatings offer improved wear resistance as a result of hard phases dispersed in binder-rich regions. However, the presence of hard and soft phases within the coating can also lead to the formation of micro-galvanic couplings in aqueous environments leading to some reduction in combined wearcorrosion resistance. Furthermore, the coating also responds differently to change in mechanical loading conditions. This chapter examines the wear-corrosion performance of thermal spray coatings in a range of wear, electrochemical, and wear-corrosion tests under varying contact conditions to develop models and establish relationships between wear mechanisms, wear rates, and environmental factors such as pH and applied load.
The wear resistance of thermal spray the tungsten and chromium carbides coatings
Journal of achievements in materials and manufacturing engineering, 2011
Purpose: The objective of the work concerns of wear-resistance of different kinds of thermal spray coatings covering industrial fun blades. The coatings were sprayed onto the fun blades by Plasma Spraying and High Velocity Oxygen Fuel Spraying (HVOF) methods. The Cr3C2, WC and also its compositions were sprayed into the fun blades. The coatings were tested in industry conditions and the effect of influence of centrifugation industry emissions on the stage of the wearing after the exploitation was compared for deposited coatings. Design/methodology/approach: The investigations of coating microstructures by optical microscopy (MO) and transmission electron microscopy (TEM) were performed. The examination of fun blades after the exploitation and the analysis of the obtained results was correlated with the performed microstructure observations and microhardness data of coatings. Findings: The microstructures of Cr and W carbides coatings were observed and analyzed. The microhardness of ...
Wear mechanisms of 13 Cr steel thermally sprayed coatings
2015
Arc wire spray is a well established method to deposit metallic wires to protect mechanical components from wear and corrosion. 13Cr steel coatings were produced using arc wire spray method. Microstructure of coating was investigated by MO and SEM. Composition and structure were determined using EDS and RDX. Coatings present a lamellar microstructure with the presence of oxides, pores, and unmelted particles. Mechanical properties were evaluated by microhardness Vickers. The wear test was conducted by ball-on-disc apparatus according to ASTM G99. The aim of this work is to study the wear mechanism by SEM observation of worn tracks.
Metallic Materials, 2018
The beds of the lathe and slides are subjected to abrasive and fatigue wear, which significantly affects their working life. The objective of this study is to enhance the useful life of the beds and slides. Detonation gun (D-Gun) sprayed WC-Co-Cr and Al2O3 + 40TiO2 coatings on cast iron imitating lathe machine beds and slides with bare metal are analysed. The wear tests were performed on pin-on-disc apparatus using ASTM G99 standard for the uncoated and coated samples of cast iron. Coatings have been characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis. The results of coating characterization, experimental wear data generated, SEM micrographs along with energy dispersive spectroscopy (EDS) of the worn samples were used to analyse the wear behaviour of coated and uncoated cast irons. The results show that WC-Co-Cr and Al2O3 + 40TiO2 coatings have been successfully deposited on cast iron by detonation gun spray process. The coated material has shown significantly less wear loss as compared to the uncoated material. The cumulative weight loss for detonation sprayed coatings increases with increase in load. The WC-Co-Cr coating has undergone minimum wear. Thus WC-Co-Cr coating deposited on cast iron has shown minimum wear as compared to Al2O3 + 40TiO2 coated and uncoated cast iron. K e y w o r d s : thermal spray coatings, tungsten carbide cobalt chromium (WC-Co-Cr), aluminium oxide + titanium oxide (Al2O3 + 40TiO2), wear resistance
Abstract— Today's trends in mechanical has long been characterized by very stringent requirement s, on one hand customer require high performance, light weight and long life components on other with use of minimum assets and cost. To increase the life of metal components environment effect on parts should be reduced. And this can only possible by coating. There are many methods of coating are available in market for iron composite material like Painting, Galvanizing, electroplating, thermal spray coating and many more. There is continuous research is going on all the methods. But now days to improve corrosion resistance thermal spray metal coating is widely used which gives better performance and corrosion resistance. Here on steel components three metals (Al, Zn, Al-Zn alloy) are thermal spray coated and analyze for corrosion resistance.
Tribological Behaviour of Thermally Sprayed Coatings: A Review
SSRN Electronic Journal, 2018
Coatings are used for modifying the surface properties of critical components subjected to mechanisms such as corrosion, oxidation, wear, or under an excessive heat load failure. Selection of the coating material and method of depositions are very important for any application. Coatings are effectively and economically used to guard the substrate surface from wear also to reduce friction. The tribological response of a coating system depends on many factors like coating properties, counterpart, substrate, interface, and running conditions. Hence, selection of the appropriate coating for a given tribological application is difficult. Thermally sprayed WC and CrC based cermet coatings are extensively used in the hydro turbine for resistance to wear like abrasive, erosive and cavitation. The NiCrAlY coating showe d better resistance to high-temperature oxidation and corrosion due to the formation of protective oxides. At high temperature working environment and chemically aggressive condition NiCrSiBC alloy reveals a good balance between corrosion and wear resistance. The NiCrBSi coating showed a good surface finish as well as the bonding interface. This paper presented the review related to the selection of coating powder and process of protective wear resistance coating by thermal spray techniques. The effect of spraying techniques and spraying parameters on the performance of the coating is different for every coating. The wear types, powders, Plasma spray and HVOF spray methods are discussed to identify the coating for a specific application.
Corrosion and wear behaviour of HVOF spraying WC-12% Ni coating on gray cast-iron
Indian Journal of Engineering & Materials Sciences, 2021
The coatings produced with high-velocity oxygen fuel spraying technology can greatly improve wear and corrosion resistance. In this study, WC-12% Ni coating was applied on the lamellar graphite cast iron substrate. Morphologies and structures of uncoated samples and sprayed coatings were analyzed with light microscopy, scanning electron microscope, energy dispersive spectrometry and X-ray diffraction. Although their micro-hardness, porosity, abrasion and corrosion properties were studied, wear experiments were performed at normal atmospheric conditions (under room temperature and 30% humidity) in the reciprocating wear testing machine. The corrosion resistance of the coatings was measured using potentio-dynamic polarization. The results revealed that the microstructure was porous, had micro-cracks, and contained some inhomogeneous structures such as carbide. Energy dispersive spectrometry analysis revealed that the presence of phases indicated the success in coating process. It was found that the WC-12% Ni coating exhibited lower potential and lower corrosion current density compared to those of the uncoated sample.