The properties of thermal sprayed aluminium coatings on non-alloy structural steel

2019 ◽  
Vol 2 (95) ◽  
pp. 64-73
Author(s):  
A. Czupryński
Keyword(s):  
Structural Steel ◽  
Erosive Wear ◽  
Industrial Applications ◽  
Flame Spraying ◽  
Arc Spraying ◽  
Pure Aluminium ◽  
Additional Material ◽  
Aluminium Powder ◽  
Wire Arc Spraying ◽  
Wear And Corrosion Resistance

Purpose: of this paper was comparison of the structure, hardness and erosive wear of aluminium coatings produced on non-alloy structural steel S355JR (EN 10025-2) using the powder flame spraying and wire arc spraying methods. Design/methodology/approach: The latest model of flame powder sprayer and wire arc sprayer was used in the experiments. This provided very reliable spraying conditions. The additional material for flame-spraying was of Metco 54NS-1 pure aluminium powder (EN AW 1100 series). In the arc spraying process the Metco Aluminium (EN AW 1100 series) 1.6 mm diameter pure aluminium thermal spray wire was used. In each spraying technology binding alloy, i.e. Ni-Al, was employed as a primer coating. The used spray processes produced dense, abrasion and erosion resistant coatings approximal 1.0 mm thick. Aluminium coatings were characterized in accordance with ASTM G 76-95 erosion resistance tests, ASTM C 633-01 adhesion strength, HV 0.1 hardness tests and metallographic analyses. The scope of research included: preparation material for spraying, selection of properly process parameters for each sprayed technique based on preliminary technological tests, coatings manufacturing, examining the structure and tribological properties of aluminium coatings, comparison of obtained samples. Findings: The obtained results have proven superior properties of arc sprayed aluminium material coatings and have shown to be promising in industrial applications. Research limitations/implications: The presented test results are a preliminary assessment of the properties of thermally sprayed aluminium coatings. Therefore, further research is required regarding the resistance of aluminium coatings to abrasion and corrosion. Practical implications: The study is focused on selecting the best and most economical technique for manufacturing of wear and corrosion resistance aluminium coatings with a thickness of approximately 1 mm. Originality/value: It has been demonstrated that the use of a Ni-Al primer coating improves the adhesion of flame and arc sprayed aluminium coatings to steel surfaces.

Influence of Inorganic Sealant in Hot and Cold Erosive Wear in Plasma Sprayed Alumina Coating

2010 ◽  
Vol 66 ◽  
pp. 86-91 ◽  
Author(s):  
Juliane Vicenzi ◽  
Antonio S. Takimi ◽  
Ricardo B. Fonseca ◽  
Andrei Locatelli ◽  
Célia Fraga Malfatti ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Wear Rate ◽  
Erosive Wear ◽  
Critical Factor ◽  
Industrial Applications ◽  
Alumina Coating ◽  
High Porosity ◽  
Wear And Corrosion ◽  
Wear And Corrosion Resistance ◽  
Plasma Sprayed

Plasma sprayed alumina coating is applied in many industrial applications in order to promote wear and corrosion resistance. Nonetheless, high porosity remained after deposition is a critical factor because it decreases the wear resistance. Some inorganic sealants can be used to reduce the open pores and superficial micro-cracks effect, improving the wear and corrosion resistance of alumina coatings. In this work, plasma sprayed alumina coating samples were divided into two groups: i) impregnated with inorganic sealant (AlPO4) and heat treated; ii) as deposited. Erosive wear tests were carried out in an erosion rig according to ASTM G76. The samples were subjected to an erodent flux, with impact angles of 30º up to 90º, at a velocity of 50m/s and temperatures of 25°C up to 400°C. The samples were characterized by SEM, Vickers microhardness, potentiodynamic anodic polarization and erosive wear rate. Results showed that erosive wear rate of alumina impregnated coating is lower than without the sealant. The sealed alumina coating presented higher mechanical properties; improved microstructural characteristics and the sealant promoted better lamellae contact, as can be observed by less sharpness in pits formation of microstructure.

scholarly journals Hard Alloys with High Content of WC and TiC—Deposited by Arc Spraying Process

2020 ◽  
Author(s):  
Stefan Lucian Toma ◽  
Radu Armand Haraga ◽  
Daniela Lucia Chicet ◽  
Viorel Paleu ◽  
Costica Bejinariu
Keyword(s):  
High Hardness ◽  
Industrial Applications ◽  
Atmospheric Plasma ◽  
Arc Spraying ◽  
Hard Alloys ◽  
X Ray Diffraction ◽  
Additional Material ◽  
Thermal Spray Process ◽  
Spray Process ◽  
Spraying Process

Obtained by different spraying technologies: in atmospheric plasma spray, High Velocity Oxygen Fuel (HVOF) or laser cladding, the layers of hard alloys with a high content of WC and TiC find their industrial applications due to their high hardness and resistance to wear. Recognized as being a process associated with welding, the arc spraying process is a method applied industrially both in obtaining new surfaces and for reconditioning worn ones. This chapter presents the technology for obtaining ultra-hard layers based on WC and TiC - by the arc spraying process, using a classic spray device equipped with a conical nozzle system and tubular wire additional material containing ultra-hard compounds (WC, TiC). To study both the quality of deposits and the influence of thermal spray process parameters on the properties of deposits with WC and TiC content, we approached various investigative techniques, such as optical scanning microscopy (SEM), X-ray diffraction, and determination of adhesion, porosity, Vickers micro-hardness and wear resistance.

Influence of Process Parameters and Geometry of the Spraying Nozzle on the Properties of Titanium Deposits Obtained in Wire Arc Spraying

2015 ◽  
Vol 1111 ◽  
pp. 211-216
Author(s):  
Bogdan Florin Toma ◽  
Iulian Ionita ◽  
Diana Antonia Gheorghiu ◽  
Lucian Eva ◽  
Costică Bejinariu ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Process Parameters ◽  
High Speed ◽  
Electrical Current ◽  
Electric Arc ◽  
Arc Spraying ◽  
Oxide Content ◽  
Spray Parameters ◽  
Influence Of Process Parameters ◽  
Wire Arc Spraying

Influence of the process parameters and geometry of the spraying nozzle on the properties of titanium deposits obtained in wire arc spraying. Wire arc spraying is a process in which through minor modifications of the spray parameters, they can have a major impact on the coatings properties. In this paper there is presented a study on the influence of process parameters and fluid dynamics of the atomization gas on the properties of titanium deposits (14T - 99.9% Ti). For this there were used three different frontal spraying nozzles, having different geometries, and were varied the spraying gas pressure and the electrical current on three levels. There were evaluated the particles velocity, coating density, chemical composition and characteristic interface between deposition and substrate. Obviously, the high speed of the atomization gas determinate the improving of all properties, but in the same time increased the oxide content in the layer. However, the oxidation can be drastically reduced if the melting and atomization of the wire droplets is produced at the point of formation of the electric arc, and the spraying jet is designed to constrain the electric arc. The assessment of deposits adherence allowed the observation of process parameters that contribute to its improvement.

Durability of Lubricated Icephobic Coatings under Multiple Icing/Deicing Cycles

2021 ◽  
Author(s):  
Valentina Donadei ◽  
Heli Koivuluoto ◽  
Essi Sarlin ◽  
Petri Vuoristo
Keyword(s):  
Industrial Applications ◽  
Power Lines ◽  
Operational Performance ◽  
Flame Spraying ◽  
Mechanical Interlocking ◽  
Properties Of Coatings ◽  
Before And After ◽  
Outdoor Environments ◽  
One Step ◽  
Ice Adhesion

Abstract In subzero conditions, atmospheric ice naturally accretes on surfaces in outdoor environments. This accretion can compromise the operational performance of several industrial applications, such as wind turbines, power lines, aviation, and maritime transport. To effectively prevent icing problems, the development of durable icephobic coating solutions is strongly needed. Here, the durability of lubricated icephobic coatings was studied under repeated icing/deicing cycles. Lubricated coatings were produced in one-step by flame spraying with hybrid feedstock injection. The coating icephobicity was investigated by accreting ice from supercooled microdroplets using an icing wind tunnel. The ice adhesion strength was evaluated by a centrifugal ice adhesion tester. The icing performance was investigated over four icing/deicing cycles. Surface properties of coatings, such as morphology, topography, chemical composition and wettability, were analyzed before and after the cycles. The results showed an increase in ice adhesion over the cycles, while a stable icephobic behaviour was retained for one selected coating. Moreover, consecutive ice detachment caused a surface roughness increase. This promotes the formation of mechanical interlocking with ice, thus justifying the increased ice adhesion. Finally, the coating hydrophobicity mainly decreased as a consequence of the damaged surface topography. In summary, lubricated coatings retained a good icephobic level after the cycles, thus demonstrating their potential for icephobic applications.

Corrosion and Wear Protection through Micro Arc Oxidation Coatings in Aluminum and Its Alloys

2019 ◽  
Author(s):  
L. Rama Krishna ◽  
G. Sundararajan
Keyword(s):  
Corrosion Resistance ◽  
Surface Properties ◽  
High Hardness ◽  
Basic Mechanism ◽  
Industrial Applications ◽  
Corrosion Properties ◽  
Micro Arc Oxidation ◽  
Coating Formation ◽  
Wear And Corrosion Resistance ◽  
Technological Limitations

This article presents the brief overview of fairly recent and eco-friendly micro arc oxidation (MAO) coating technology. The weight-cost-performance benefits in general raised the interest to utilize lightweight materials, especially the aluminum and its alloys. Despite numerous engineering advantages, the aluminum alloys themselves do not possess suitable tribology and corrosion resistance. Therefore, improvements in surface properties are essential to enable developing potential industrial applications. For improving wear and corrosion resistance of Al alloys, the most demanding surface properties are high hardness and chemical inertness. The technical and technological limitations associated with traditional anodizing and hard anodizing processes have been the strongest driving force behind the development of new MAO technology. While presenting the key technological elements associated with the MAO process, the basic mechanism of coating formation and its phase gradient nature is presented. Influence of various process parameters including the electrolyte composition has been discussed. The typical microstructural features and distribution of α- and γ-Al2O3 phases across the coating thickness as a key strategy to form dense coatings with required mechanical, tribological, and corrosion properties which are vital to meet potential application demands are briefly illustrated.

Wires for Arc and High Velocity Flame Spraying—Wire Design, Materials, and Coating Properties

2000 ◽  
Author(s):  
J. Wilden ◽  
A. Wank ◽  
F. Schreiber
Keyword(s):  
High Velocity ◽  
Protective Coatings ◽  
Large Diameter ◽  
Flame Spraying ◽  
Arc Spraying ◽  
Coating Properties ◽  
Effective Protection ◽  
Low Degree ◽  
High Degree ◽  
Cored Wires

Abstract Cored wires show a high potential for production of protective coatings for combined corrosion and wear applications. Iron and nickel based grooved cored wires without and with different reinforcing carbide fillers have been sprayed by arc- and high velocity combustion wire (HVCW) spraying with a Praxair Type 216 gun. Depending on the wear mechanism coatings with a similar abrasive or oscillating wear resistance like HVOF WC/Co/Cr 86/10/4 have been produced. For effective protection against oscillating wear wires with a large diameter and therefore a high content of reinforcing carbide filler have to be applied. All nickel based coatings with chromium addition show an improved corrosion resistance compared to HVOF-sprayed WC/Co/Cr 86/10/4. For coatings from wires with NiCr 80/20 velum no effect of severe sulphurous corrosion in the DIN 50018 test is observed. HVCW-spraying is especially suitable, when only a low degree of interaction between velum and filler material is wanted as for cermet-like coatings. Conventional arc-spraying rather meets the demands of a high degree of interaction between velum and filler necessary for the production of pure metallic coatings like NiCrBSi. All manufactured coatings show good machinability.

A Study on the Arc Spraying of 7Cr13 Cored Wire and Tribological Properties of the Composite Coating

1998 ◽  
Author(s):  
B. Xu ◽  
S. Ma ◽  
J. Wang ◽  
J. Tan
Keyword(s):  
Bond Strength ◽  
Composite Coating ◽  
Tribological Properties ◽  
High Hardness ◽  
Wear Resistant Coating ◽  
Arc Spraying ◽  
Metallurgical Process ◽  
Cored Wire ◽  
Wear Resistant ◽  
Wire Arc Spraying

Abstract For the purpose of getting high hardness and high wear-resistant coating by arc spraying technology, the arc spraying of 7Cr13 cored wire is adopted in this paper. The metallurgical process of the cored wire arc spraying is discussed. The bond strength, hardness and tribological properties of the composite coating are investigated.

Detonation Sprayed Coatings and their Tribological Performances

2015 ◽  
pp. 294-327 ◽  
Author(s):  
D. Srinivasa Rao ◽  
G. Sivakumar ◽  
D. Sen ◽  
S.V. Joshi
Keyword(s):  
Wear Resistance ◽  
Erosive Wear ◽  
Spray Coating ◽  
Great Promise ◽  
Process Conditions ◽  
Comprehensive Overview ◽  
Cermet Coatings ◽  
Wear And Corrosion Resistance ◽  
Wear Modes ◽  
Sprayed Coatings

The Detonation Spray Coating (DSC) process is a unique variant among the wide choice of thermal spray processes. The typical functionalities of DSC coatings include wear and corrosion resistance, elevated temperature oxidation resistance, thermal barrier, insulative/conductive, abradable, lubricious surface, etc. Among the coatings for wear resistance, the cermet coatings based on WC–Co and Cr3C2–NiCr are the most popular materials of choice and contribute to bulk of the utilization by the industry towards wear resistance. Notwithstanding the above materials, alternative materials involving modifications in both hard and binder phases like TiMo (CN)–NiCo, WC-CrC-Ni, WC-Co-Cr, WC-Ni, Cr3C2-Ni, Cr3C2-Inconel, etc. exhibit great promise towards tribological applications under diverse wear modes. This chapter on the tribological characteristics of the detonation sprayed coatings provides a comprehensive overview on the characteristics of various cermet coatings generated at varied process conditions and its influence on the tribological properties under abrasive, sliding, and erosive wear modes.

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