scholarly journals Understanding the Influence of High Velocity Thermal Spray Techniques on the Properties of Different Anti-Wear WC-Based Coatings

Coatings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1157
Author(s):  
Andrea Garfias Bulnes ◽  
Vicente Albaladejo Fuentes ◽  
Irene Garcia Cano ◽  
Sergi Dosta
Keyword(s):  
Grain Size ◽  
Corrosion Resistance ◽  
Abrasive Wear ◽  
Thermal Spray ◽  
High Velocity ◽  
Metallic Matrix ◽  
High Hardness ◽  
Hard Metal ◽  
Characterization Methods ◽  
X Ray

This work analyzes the differences found in hard metal coatings produced by two high velocity thermal spray techniques, namely high velocity oxy-fuel (HVOF) and high velocity air-fuel (HVAF). Additionally, the effect of the metallic matrix and ceramic composition and the original carbide grain size on coating properties is compared to the most studied standard reference material sprayed by HVOF, WC-Co. For this evaluation, the physical properties of the coatings, including feedstock characteristics, porosity, thickness, roughness, hardness, and phase composition were investigated. Several characterization methods were used for this purpose: optical microscopy (OM), scanning electronic microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS), and X-ray Diffraction (XRD), among others. The final performance (abrasive wear and corrosion resistance) shown by the coatings obtained by these two methodologies was also analyzed. Thus, the abrasive wear resistance was analyzed by the rubber-wheel test, while the corrosion resistance was characterized with electrochemical methods. The characterization results obtained clearly showed that the coatings exhibit different microstructures according to feedstock powder characteristics (carbide grain size and/or composition) and the thermal spray process used for its deposition. Thus, the incorporation of WB to the cermet composition led to a high hardness coating, and the complementary hardness and toughness of the WC-Co coatings justify its better abrasion resistance. The presence of Ni on the metal matrix increases the free corrosion potential of the coating to more noble region. However, the WC-Co coatings show a lower corrosion rate and hence a higher protective performance than the rest of the coatings.

Effect of Ti and Sb Elements Addition on the Microstructure and Corrosion Resistance of Hot-Dip Galvanized Zn-11Al-3Mg Alloy

2021 ◽  
Vol 1035 ◽  
pp. 630-637
Author(s):  
Hui Jie Sun ◽  
Guo Rong Zhou ◽  
Ming Ming Zhang ◽  
Xue Feng Wang ◽  
Shui Yu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Grain Size ◽  
Corrosion Resistance ◽  
Energy Dispersive Spectrometry ◽  
X Ray Diffraction ◽  
Rich Phase ◽  
X Ray ◽  
Pitting Corrosion Resistance ◽  
Scanning Electron

The effect of Ti and Sb elements addition on the microstructures and corrosion resistance of hot-dip galvanized Zn-11Al-3Mg alloy was investigated by scanning electron microscopy (SEM) equipped with energy dispersive spectrometry (EDS), X-ray diffraction (XRD) and Electrochemical workstation, respectively. Results showed that the grain size of the alloy was obviously refined with the addition of Ti and Sb elements, due to Al3Ti phase as the nucleation substrate resulted in the transformation of Al-rich phase from dendrite to petal-like. In addition, the pitting corrosion resistance of the alloy has been significantly enhanced.

The influence of WC grain size on the durability of WCCo cutting edges in the machining of wood-based materials

2019 ◽  
Vol 107 ◽  
pp. 65-71
Author(s):  
JOANNA WACHOWICZ ◽  
JACEK WILKOWSKI ◽  
KLAUDIA WIERZBICKA ◽  
PAWEŁ CZARNIAK
Keyword(s):  
Grain Size ◽  
Abrasive Wear ◽  
Tungsten Carbide ◽  
High Resistance ◽  
Cutting Tools ◽  
High Hardness ◽  
Fold Increase ◽  
Cemented Carbides ◽  
Materials Used

WCCo cemented carbides are one of the basic materials used for tools. They consist of tungsten carbide in 70–96% and a binding warp – cobalt. High hardness of these materials determines their high resistance to abrasive wear. These properties predispose them to be used as a material for cutting tools. This study presents the results of tests on the durability of cutting edges made of WCCo composite of different WC grain in the machining of wood-based materials. The tests showed a several-fold increase of the durability of edges made of WCCo composite of grain size of 0.2÷0.5 μm compared to WCCo blades of WC grain size of 0.5÷0.8 μm and 0.8÷1.3 μm.

scholarly journals Nd:YVO4 Laser Irradiation on Cr3C2-25(Ni20Cr) Coating Realized with High Velocity Oxy-Fuel Technology—Analysis of Surface Modification

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1477
Author(s):  
Luca Giorleo ◽  
Giovina Marina La Vecchia ◽  
Elisabetta Ceretti
Keyword(s):  
Surface Modification ◽  
High Velocity ◽  
Laser Scanning ◽  
High Hardness ◽  
Hard Metal ◽  
Machining Process ◽  
Laser Source ◽  
Thermal Source ◽  
Powder Particles ◽  
Mechanical Machining

The high-velocity oxy-fuel (HVOF) technique has been extensively used for the deposition of hard metal coatings. The main advantage of HVOF, compared to other thermal spray techniques, is its ability to accelerate the melted powder particles of the feedstock material to a relatively high velocity, leading to good adhesion and low porosity. To further improve the surface properties, a mechanical machining process is often needed; however, a key problem is that the high hardness of the coating makes the polishing process expensive (in terms of time and tool wear). Another approach to achieving surface modification is through interaction with a thermal source, such as a laser beam. In this research, the effects of laser scanning rate, scanning strategy, and number of loop cycles were investigated on an HVOF-coated surface. Cr3C2-25(Ni20Cr) was selected as the coating and Nd:YVO4 as the laser source. The results demonstrate the significance of the starting coating morphology and how the laser process parameters can be tuned to generate different types of modifications, ranging from polishing to texturing.

scholarly journals Nanocomposite Coatings: Preparation, Characterization, Properties, and Applications

2018 ◽  
Vol 2018 ◽  
pp. 1-19 ◽  
Author(s):  
Phuong Nguyen-Tri ◽  
Tuan Anh Nguyen ◽  
Pascal Carriere ◽  
Cuong Ngo Xuan
Keyword(s):  
Metallic Matrix ◽  
High Hardness ◽  
Diffusion Path ◽  
Barrier Properties ◽  
Preparative Method ◽  
Nanocomposite Coating ◽  
Nanocomposite Coatings ◽  
Characterization Methods ◽  
Properties And Characterization ◽  
Potential Applications

Incorporation of nanofillers into the organic coatings might enhance their barrier performance, by decreasing the porosity and zigzagging the diffusion path for deleterious species. Thus, the coatings containing nanofillers are expected to have significant barrier properties for corrosion protection and reduce the trend for the coating to blister or delaminate. On the other hand, high hardness could be obtained for metallic coatings by producing the hard nanocrystalline phases within a metallic matrix. This article presents a review on recent development of nanocomposite coatings, providing an overview of nanocomposite coatings in various aspects dealing with the classification, preparative method, the nanocomposite coating properties, and characterization methods. It covers potential applications in areas such as the anticorrosion, antiwear, superhydrophobic area, self-cleaning, antifouling/antibacterial area, and electronics. Finally, conclusion and future trends will be also reported.

Interfacial Elemental Distribution In Tungsten Carbide Coated Steel

1999 ◽  
Vol 5 (S2) ◽  
pp. 838-839
Author(s):  
S.V. Naidu ◽  
Carlos Green ◽  
Christopher Maxie ◽  
James D. Garber ◽  
Gary A. Glass
Keyword(s):  
Thermal Spray ◽  
Steel Substrate ◽  
Spray Coating ◽  
High Hardness ◽  
Thermal Spray Coating ◽  
Elemental Distribution ◽  
Coated Steel ◽  
X Ray ◽  
Carbide Coatings ◽  
Steel Substrates

Thermal spray of carbide coatings with high hardness and corrosion resistance onto steel substrates has technological importance. The adhesive strength is greatly effected by the interfacial impurities. Low porous and good quality 200 μm thick 86WC10Co4Cr coatings on 4140 steel are obtained by thermal spray methods using SC-HVOF gun at Cooper Oil Tools, Houston, TX. A Carl Zeiss DSM942 SEM with 3.5 nm resolution at 30 keV and Kevex LPX1 Super Dry Quantum Si(Li) Detector with < 145 eV resolution for Energy Dispersive X-ray Spectroscopy (EDXS) were used to study the elemental distribution across the interface. Fig. 1 shows the SEM micrographs of the interface between 86WC10Co4Cr thermal spray coating and 4140 steel substrate. The anchor patterns seen at the interface are believed to improve the adhesive qualities between the coating and the substrate.

Aspects of microanalysis in a transmission electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 510-511
Author(s):  
R. Sinclair ◽  
B.E. Jacobson
Keyword(s):  
Grain Size ◽  
Electron Beam ◽  
Electron Microscope ◽  
Chemical Analysis ◽  
Transmission Electron Microscope ◽  
Vapor Deposition ◽  
Critical Currents ◽  
X Ray ◽  
Fine Grain ◽  
Transmission Electron

INTRODUCTIONThe prospect of performing chemical analysis of thin specimens at any desired level of resolution is particularly appealing to the materials scientist. Commercial TEM-based systems are now available which virtually provide this capability. The purpose of this contribution is to illustrate its application to problems which would have been intractable until recently, pointing out some current limitations.X-RAY ANALYSISIn an attempt to fabricate superconducting materials with high critical currents and temperature, thin Nb3Sn films have been prepared by electron beam vapor deposition [1]. Fine-grain size material is desirable which may be achieved by codeposition with small amounts of Al2O3 . Figure 1 shows the STEM microstructure, with large (∽ 200 Å dia) voids present at the grain boundaries. Higher quality TEM micrographs (e.g. fig. 2) reveal the presence of small voids within the grains which are absent in pure Nb3Sn prepared under identical conditions. The X-ray spectrum from large (∽ lμ dia) or small (∽100 Ǻ dia) areas within the grains indicates only small amounts of A1 (fig.3).

REYNOLDS 390 and A390

Alloy Digest ◽  
1971 ◽  
Vol 20 (8) ◽  
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
High Hardness ◽  
Heat Treating ◽  
Silicon Alloys ◽  
Aluminum Silicon Alloys ◽  
Temperature Performance

Abstract REYNOLDS 390 and A390 are hypereutectic aluminum-silicon alloys having excellent wear resistance coupled with good mechanical properties, high hardness, and low coefficients of expansion. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fatigue. It also includes information on high temperature performance and corrosion resistance as well as casting, heat treating, and machining. Filing Code: Al-203. Producer or source: Reynolds Metals Company.

DOWMETAL ZK60A

Alloy Digest ◽  
1952 ◽  
Vol 1 (1) ◽  
Keyword(s):  
Fracture Toughness ◽  
Grain Size ◽  
Corrosion Resistance ◽  
High Resistance ◽  
High Strength ◽  
Heat Treating ◽  
Bend Strength ◽  
Chemical Company ◽  
Resistance To Stress ◽  
Extrusion Alloy

Abstract Dowmetal ZK60A is an ageable extrusion alloy for use where high strength magnesium extrusions with good toughness are required. It has small grain size, low notch sensitivity and a relatively high resistance to stress corrosion. This datasheet provides information on composition, physical properties, tensile properties, and compressive, shear, bearing, and bend strength as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Mg-1. Producer or source: The Dow Chemical Company.

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