The Influence of Thermally Sprayed Coatings Microstructure on their Mechanical and Tribological Characteristics

2007 ◽  
Vol 567-568 ◽  
pp. 229-232 ◽  
Author(s):  
Šárka Houdková ◽  
František Zahálka ◽  
Michaela Kašparová
Keyword(s):  
Wear Resistance ◽  
Composite Coatings ◽  
Erosive Wear ◽  
Proper Function ◽  
Wear Resistant Coatings ◽  
Technology Process ◽  
Pin On Disc ◽  
Impact Angles ◽  
Mechanical And Tribological Characteristics ◽  
Thermally Sprayed

The tribological properties of parts surface, namely their wear resistance and friction properties, are in many cases determining for their proper function. To improve surface properties, it is possible to create hard, wear resistant coatings by thermal spray technologies. Using these versatile coatings it is possible to increase parts lifetime, reliability and safety. The thermally sprayed cermet composite coatings show, thanks to their specific properties, excellent resistance to abrasive and erosive wear, as well as corrosion resistance. To predict the behavior, lifetime and application area of thermally sprayed cermet coatings it is necessary to completely understand the relationships between technology, process parameters, microstructure and properties of the coatings. The finding of these relationships and use this understanding to develop deposits with improved wear resistance for coating of various applications is the main aim of the presented work. It was done by studying the coatings microstructure and mechanical properties. Four different tests of wear resistance were done to study the mechanism of surface degradation, to confirm the results of mechanical testing and to predict the lifetime of coated parts - the abrasive wear performance of the coatings was assessed using a dry/sand rubber wheel test according to ASTM G-65, wet slurry abrasion test according to ASTM G-75, pin-on-disc test according to ASTM G-99 and erosion wear resistance for three impact angles. On the basis of obtained data the new possibilities of coatings application was determined, tested and implemented.

Tribological Performance Study of HVOF-Sprayed Microstructured and Nanostructured WC-17wt.%Co Coatings

2010 ◽  
Author(s):  
Gobinda C. Saha ◽  
A. Mateen ◽  
Tahir I. Khan
Keyword(s):  
Wear Resistance ◽  
Wear Rate ◽  
Oil Sands ◽  
Composite Coatings ◽  
Surface Hardness ◽  
Erosive Wear ◽  
Fusion Welding ◽  
Performance Study ◽  
Ductile Phase ◽  
The Core

Abrasive and erosive wear of components and machinery is an ongoing challenge in the oil sands industry in northern Alberta, Canada. To improve the wear resistance by increasing surface hardness of steels, heat treatments and deposition of hard layers of metal alloys (such as stellite) by fusion welding techniques are traditionally used. However, these deposition techniques are not applicable to all shapes and add considerable weight to the final component. Thermal spraying techniques such as the use of high velocity oxy-fuel (HVOF) composite coatings based on WC-Co cermet system offer better wear resistance and greater flexibility in applications. This study presents work on two feedstock powders, namely nanocrystalline and microcrystalline WC-Co cermets, with identical matrix phase content: WC-17wt.%Co. The novelty of the research is that an engineered duplex Co coated WC-17wt.%Co cermet particle designed to withstand coating spalling under elevated loads as well as to limit abrasive debridement during wear is introduced for the first time to produce a more homogeneously-dispersed coating microstructure. The engineered particle has 6wt.% of the ductile phase material mixed into the core to insure that the reinforcement WC phase is discontinuous to limit the debridement during wear, while remainder (11wt.%) of the Co is applied as a coating on the particle to improve the ductility. The mechanical properties of the overall particle are further improved by controlling the size of the reinforcing phase (WC) in the matrix (Co). This resulted in a WC-17wt.%Co particle containing a characteristic WC grain in the order of 350 nm in the core with the Co outer coating of 1–2 μm thick, making the powder particle as nanocrystalline. HVOF deposited coatings of the nanocrystalline and microcrystalline powders were examined for microhardness, fracture toughness, sliding abrasion (ASTM G133-05) and dry-sand rubber wheel abrasion (ASTM G65-04) wear performance. The wear rate under various loads and sliding distances was studied. In both the coatings, it was found that the wear rate increased with increasing applied loads, while it decreased with increasing sliding distances. 3D surface analysis of the wear tracks using atomic force microscopy (AFM) revealed two distinctive mechanisms associated with the two coatings after abrasive wear. The improved wear resistance was attributed to the higher hardness value of the nanostructured WC-17wt.%Co coating. It was also found that the nanostructured WC-17wt.%Co coating has about twice the toughness of the conventional microstructured coating counterpart. The extent of the WC decarburization and the dissolution of Co in the coatings were also studied.

scholarly journals Electrodeposition of Transition Metal Composites on Mild Steel: Structural and Wear Behaviour

2019 ◽  
Vol 8 (6S) ◽  
pp. 534-539
Keyword(s):  
Wear Resistance ◽  
Transition Metal ◽  
Mild Steel ◽  
Composite Coatings ◽  
Wear Behaviour ◽  
Metal Composite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pin On Disc ◽  
Structural Characterizations

Wear characteristics of the transition metal composite (TMC) coated mild steel are investigated. TMC coatings were performed using electrodeposition technique on mild steel. Different concentrations of transition metals were subjected to prepare the TMC’s and studied. The structural and the micro structural studies of the composites coatings were studied through X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The elemental compositions of coated composites were evaluated using Energy dispersive X-ray diffraction (EDS) studies. Both the structural and micro structural characterizations confirmed the formation of composite coatings. Further, it is evident from the EDS analyses that TMC’s are coated with the desired concentrations. In order to understand the wear resistance of coated mild steel, the specimen were subjected to load on pin-on-disc type wear tester. The effects of concentration of composite and thickness of the coating on wear resistance are discussed. The coating results in improving the wear resistance and hardness of the specimen

scholarly journals Evaluation of the Wear Resistance and Corrosion Behavior of Laser Cladding Al/SiC Metal Matrix Composite Coatings on ZE41 Magnesium Alloy

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 639
Author(s):  
Ainhoa Riquelme ◽  
Pilar Rodrigo ◽  
María Dolores Escalera-Rodriguez ◽  
Joaquín Rams
Keyword(s):  
Wear Resistance ◽  
Magnesium Alloy ◽  
Corrosion Behavior ◽  
Laser Cladding ◽  
Wear Behavior ◽  
Composite Coatings ◽  
Aluminum Matrix ◽  
Aluminum Matrix Composites ◽  
Wear Rates ◽  
Pin On Disc

Aluminum matrix composites reinforced with SiC particles (SiCp) were deposited on ZE41 magnesium substrates by laser cladding in order to improve their tribological performance. Silicon and titanium were added to the matrix in order to avoid Al-SiC reactivity. The addition of these elements to avoid Al4C3 formation during the laser cladding fabrication was successfully explored in previous research, but the effect of these elements on the wear behavior and the corrosion resistance of these coatings has not been studied. During the fabrication process, there is dilution with the substrate that forms an Al-Mg matrix, which has an influence on the wear and corrosion behavior. Electrochemical polarization and impedance measurements in a 3.5% NaCl solution and the dry sliding conditions on a pin-on-disc tribometer were used to evaluate the different compositions of Al/SiCp coatings on the ZE41 magnesium alloy and uncoated ZE41. All of the composite coatings had lower wear rates than the substrate. However, the coatings showed worse corrosion behavior than the ZE41 substrate, although the addition of Si or Ti improves the corrosion behavior and the wear resistance.

Wear and Corrosion Resistance of Ni-PTFE-SiO2 Composite Coating Deposited by Jet Electrodeposition

2008 ◽  
Vol 373-374 ◽  
pp. 597-600 ◽  
Author(s):  
Wen Song Lin ◽  
Shi Qiang Qian ◽  
Xu Wen Chen
Keyword(s):  
Wear Resistance ◽  
Composite Coatings ◽  
Anodic Polarization Curve ◽  
Experimental Conditions ◽  
Corrosion Resistant ◽  
Wear And Corrosion ◽  
Jet Electrodeposition ◽  
Pin On Disc ◽  
Jet Velocity ◽  
Wear And Corrosion Resistance

Ni-PTFE/SiO2 composite coatings were prepared by jet electrodeposition. The influences of the particles contents and jet velocity on the properties of the composite coatings were studied. The morphology and microstructure of the coatings were observed on an S-2700 scanning electron microscopy. HX-1 microhardness tester was used to determine the hardness of the coatings. The deposition rate were determined by means of the coatings thickness. The adhesion strength was measured using a scratch tester. Wear resistance tests were performed using a pin-on-disc tribometer with the sample placed horizontally on a turning table. The corrosion behavior of the coatings immersed in 10% H2SO4 solution was analyzed using anodic polarization curve measurement. It was shown that the microhardness of the coatings increased with the increase of SiO2 content, while the addition of PTFE in the coatings resulted in better corrosion-resistant property. Enhancing the jet velocity made the coating compacter. Ni-PTFE-SiO2 composite coatings demonstrated superior wear resistance to Ni-PTFE or Ni-SiO2 coatings under the experimental conditions.

Study of Slurry Erosive Wear Behavior of Titania-30 Wt% Inconel-718 Plasma Sprayed Mild Steel Using Taguchi Technique

2015 ◽  
Vol 813-814 ◽  
pp. 111-115
Author(s):  
C.S. Ramesh ◽  
R. Suresh Kumar ◽  
G. Dilip Maruthi ◽  
R. Rashmi
Keyword(s):  
Wear Resistance ◽  
Mild Steel ◽  
Wear Behavior ◽  
Steel Substrate ◽  
Composite Coatings ◽  
Erosive Wear ◽  
Wear Test ◽  
Silica Sand ◽  
Slurry Erosion ◽  
Uncoated Sample

Surface coating is sharing the responsibility between coating and substrate, which enhances the surface properties such as strength, hot hardness and toughness, wear resistance, antifriction and chemical inertness. The present work is focused on wear behavior of Mild Steel substrate material deposited with Titanium dioxide-30 wt % of Inconel718 incorporating plasma spray process. These composite coatings were subjected to slurry erosion wear test by simulating the corrosive-erosive atmosphere by mixing of silica sand and 3.5 percent of NaCl in distilled water. Under identical conditions, coated mild steels gave better wear resistance compared to uncoated sample.

scholarly journals HVOF Sprayed Fe-Based Wear-Resistant Coatings with Carbide Reinforcement, Synthesized In Situ and by Mechanically Activated Synthesis

Coatings ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1092
Author(s):  
Dmytro Tkachivskyi ◽  
Kristjan Juhani ◽  
Andrei Surženkov ◽  
Priit Kulu ◽  
Tomáš Tesař ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Composite Coatings ◽  
Thermal Spraying ◽  
Steel Matrix ◽  
X Ray Diffraction ◽  
Hvof Spraying ◽  
Wear Resistant ◽  
Wear Resistant Coatings ◽  
Two Phases

The aims of this study were: (1) to produce composite coatings by high velocity oxy fuel (HVOF) spraying with steel matrix reinforced by cermets (a) Cr3C2–20%Ni and (b) TiC–20%NiMo, manufactured by mechanically activated synthesis (MAS); (2) to synthesize in situ a carbide reinforcement for iron matrix from a mixture of titanium and carbon during HVOF reactive thermal spraying (RTS); (3) to compare the wear resistance of produced coatings. As a reference, HVOF sprayed coatings from commercial Cr3C2–25%NiCr (Amperit 588.074) and AISI 316L were utilized. Study of microstructure revealed the inhomogeneity of the Cr-based MAS coating; the Ti-based MAS coating had typical carbide granular structure, and the Ti-based RTS coating possessed elongated structures of TiC. The X-ray diffraction revealed two main phases in the Cr-based MAS coating: Cr3C2 and austenite, and two phases in the Ti-based coatings: TiC and austenite. Among the studied coatings, the Cr-based MAS coating demonstrated the highest low-force hardness (490 HV0.3). During the abrasive rubber wheel test (ASTM G65), the Ti-based MAS coating showed the best wear resistance, followed by Cr3C2–25%NiCr and Ti-based RTS coating. In the abrasive–erosive test (GOST 23.201-78), the Ti-based MAS coating was 44% better than Cr3C2–25%NiCr coating. The Ti-based RTS coating was 11% more wear resistant than the reference Cr3C2–25%NiCr coating.

scholarly journals Effect of basalt and silica additives on erosive wear resistance of cast ceramics

2016 ◽  
Vol 65 (2) ◽  
pp. 144 ◽  
Author(s):  
J Baronins ◽  
M Antonov ◽  
R Ivanov ◽  
V Shuliak ◽  
I Hussainova
Keyword(s):  
Wear Resistance ◽  
Erosive Wear
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