Microstructure and Hardness of Fe-Based Coating by Plasma Cladding

2013 ◽  
Vol 376 ◽  
pp. 144-147
Author(s):  
Li Mei Wang ◽  
Jun Bo Liu ◽  
Jun Sheng Jiang
Keyword(s):  
Electron Microscopy ◽  
Electron Probe ◽  
Composite Coatings ◽  
Micro Hardness ◽  
Hard Phase ◽  
Hardness Tester ◽  
Electron Probe Micro Analyzer ◽  
Average Hardness ◽  
Plasma Cladding ◽  
Scanning Electron

Plasma cladding experiments were carried out on Q235 steel with Fe-Cr-Ti-C powder. Microstructure and micro-hardness of the composite coatings were investigated by means of optical microscopy (OM), scanning electron microscopy (SEM) and electron probe micro-analyzer (EPMA) and micro-hardness tester. The results indicated that the grains of the cladding coatings with Ti are much finer than that of the Fe-based cladding coating without Ti. Compared with the cladding coatings without Ti, there are more shingle crystals in the cladding coatings with Ti and the hard phase (Cr,Fe)7C3 of the eutectic in the coatings increase gradually. The average hardness value of the four cladding coatings is respectively 486.5 HV0.1and 558.8 HV0.1.

Investigation on Recovery and Recrystallization of Al-Si-Al2O3 Composites

2013 ◽  
Vol 813 ◽  
pp. 345-350
Author(s):  
Xiong Wei Wang ◽  
Xiao Song Jiang ◽  
De Gui Zhu ◽  
Luo Zhang
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Optical Microscope ◽  
In Situ Synthesis ◽  
Recrystallization Temperature ◽  
Recrystallization Behavior ◽  
Micro Hardness ◽  
Hardness Tester ◽  
Scanning Electron

Al-Si-Al2O3 composites were prepared by powder metallurgy with in-situ synthesis technology. The recovery and recrystallization behavior of Al-Si-Al2O3 composites which underwent compression and then heat-treatment under different temperature were studied using micro-hardness tester, optical microscope (OM) and scanning electron microscopy (SEM) . The results showed that the hardness of composites increased dramatically after compression, and the sample containing 5wt% Si was increasing more evidently than the sample including 10wt%Si. Heat treatment gradually eliminated work hardening; meanwhile the fact that the hardness of composites trended to decline greatly when subjected to annealing suggested occurrence of recovery and recrystallization inside the composites. Recrystallization nucleation preferentially took place in the region near the particle, while the growth of recrystallized grains can also be hindered owning to the pining effect of particles. Depending on the analysis of microstructure and microhardness, it can be concluded that the recrystallization temperature of Al-wt.5%Si-Al2O3 composites was 500°C and the Al-wt.10%Si-Al2O3 composites was 525°C.

Application of Laser Additive Enhancing Technology in the Field of Cutting Tools

2017 ◽  
Vol 872 ◽  
pp. 8-13
Author(s):  
Yuan Ren ◽  
Wen Tao Wang ◽  
Xin Qiang Ma ◽  
Wei Cheng
Keyword(s):  
Grain Boundary ◽  
Cutting Tools ◽  
Alloy Coating ◽  
Optical Microscope ◽  
Solid State Laser ◽  
Micro Hardness ◽  
Hard Phase ◽  
Hardness Tester ◽  
Scanning Electron ◽  
Steel Cutting

Fe62 alloy coating was fabricated on the surface of #45 steel cutting edges with 2kW all-solid-state laser and powder feeding device. The substrate and forming layer are characterized by optical microscope and scanning electron microscope for microstructure, and tested by micro-hardness tester for micro-hardness. The results show that the forming layer combined with the substrate metallurgically. The microstructure of substrate is eutectoid ferrite and pearlite. The microstructure of layer is uniform and compact, with hard precipitation. The content of Cr, the hard phase generated element, at the grain boundary, is higher than that of grain inside and many hard phases were generated at the grain boundary. Compared with the substrate, the micro-hardness of forming layer increases by about 2 times. All these results show that application of laser additive enhancing technology in the field of cutting tools has larger potential.

scholarly journals Comparative performances of Ni-SiC composite coatings deposited by conventional and brush electroplating

2019 ◽  
Vol 14 (9) ◽  
pp. 105
Author(s):  
Bui Thi Thao Nguyen ◽  
Nguyen Thanh Loc
Keyword(s):  
Electron Microscopy ◽  
Composite Coatings ◽  
Energy Dispersive Spectrometer ◽  
Hardness Test ◽  
Electrochemical Technique ◽  
Micro Hardness ◽  
Plating Bath ◽  
Plating Solution ◽  
Materials Used ◽  
Scanning Electron

SiC particles are known as reinforced materials used to improve the coating’s properties and performances. In this paper, Ni - SiC composite coatings were deposited by conventional electroplating from sulfate-chloride bath, and brush electroplating methods from modified chloride bath with different dispersed SiC contents. The plating conditions were investigated and the process’ parameters were defined through electrochemical technique. Scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) and micro-hardness test were used to clarify the effect of SiC content on coating’s properties and performances. The hardness of brush electrodeposit reached the highest value of 525 HV when the concentration of SiC in the plating solution was 4 g/L, while the hardness of conventional electrodeposit was only 389.3 HV when the plating bath contained 20 g/L SiC. The characterized results show clear advantages of brush electroplating compared to the conventional method to form the coating with high micro-hardness.

scholarly journals Investigations on the oxidation of Zn-coated steel cables

2021 ◽  
Vol 49 (3) ◽  
pp. 587-597
Author(s):  
Gustavo Pinto ◽  
F.J.G. Silva ◽  
A. Baptista ◽  
Raul Campilho ◽  
F. Viana
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Probe ◽  
Steel Wire ◽  
Coated Steel ◽  
Steel Cable ◽  
Electron Probe Micro Analyzer ◽  
Steel Cables ◽  
Automotive Component Industry ◽  
Scanning Electron

The automotive component industry has been constantly being studying to improve its performance. Bowden cables are present in opening doors, moving windows and others. In braided cables formed by galvanized wires with Zn steel exposed to the usual environmental conditions, the generation of ZnO appears, a phenomenon known as "white corrosion". The investigation consisted of mitigating the causes of the ZnO formation. Scanning electron microscopy (SEM) and Electron Probe Micro-Analyzer (EPMA) technology, allowed to detect that the generation of ZnO was induced by the presence of nucleating elements of ZnO on the surface of the steel cable before galvanizing with Zn. The S, Cl and O became visible in the interface between coating and substrate. This allowed concluding, under the coating, there were harmful products capable of triggering the ZnO nucleation reaction. So, the storage and cleaning of the steel wire before galvanizing is essential to prevent the ZnO formation.

High Resolution Scanning Electron Microscopy

1991 ◽  
Vol 49 ◽  
pp. 478-479
Author(s):  
David Joy ◽  
James Pawley
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Beam ◽  
Electron Microscope ◽  
High Resolution ◽  
Scanning Electron Microscope ◽  
Electron Probe ◽  
Impact Point ◽  
Interaction Volume ◽  
Scanning Electron

The scanning electron microscope (SEM) builds up an image by sampling contiguous sub-volumes near the surface of the specimen. A fine electron beam selectively excites each sub-volume and then the intensity of some resulting signal is measured. The spatial resolution of images made using such a process is limited by at least three factors. Two of these determine the size of the interaction volume: the size of the electron probe and the extent to which detectable signal is excited from locations remote from the beam impact point. A third limitation emerges from the fact that the probing beam is composed of a finite number of discrete particles and therefore that the accuracy with which any detectable signal can be measured is limited by Poisson statistics applied to this number (or to the number of events actually detected if this is smaller).

scholarly journals Surface Properties of Silica–MWCNTs/PDMS Composite Coatings Deposited on Plasma Activated Glass Supports

2021 ◽  
Vol 11 (19) ◽  
pp. 9256
Author(s):  
Michał Chodkowski ◽  
Iryna Ya. Sulym ◽  
Konrad Terpiłowski ◽  
Dariusz Sternik
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Scanning Electron Microscopy ◽  
Multiwalled Carbon Nanotubes ◽  
Composite Coatings ◽  
Thermal Analyses ◽  
Sol Gel ◽  
Visible Range ◽  
Multiwalled Carbon ◽  
Scanning Electron

In this paper, we focus on fabrication and physicochemical properties investigations of silica–multiwalled carbon nanotubes/poly(dimethylsiloxane) composite coatings deposited on the glass supports activated by cold plasma. Air or argon was used as the carrier gas in the plasma process. Multiwalled carbon nanotubes were modified with poly(dimethylsiloxane) in order to impart their hydrophobicity. The silica–multiwalled carbon nanotubes/poly(dimethylsiloxane) nanocomposite was synthesized using the sol–gel technique with acid-assisted tetraethyl orthosilicate hydrolysis. The stability and the zeta potential of the obtained suspension were evaluated. Then, the product was dried and used as a filler in another sol–gel process, which led to the coating application via the dip-coating method. The substrates were exposed to the hexamethyldisilazane vapors in order to improve their hydrophobicity. The obtained surfaces were characterized by the wettability measurements and surface free energy determination as well as optical profilometry, scanning electron microscopy, and transmittance measurements. In addition, the thermal analyses of the carbon nanotubes as well as coatings were made. It was found that rough and hydrophobic coatings were obtained with a high transmittance in the visible range. They are characterized by the water contact angle larger than 90 degrees and the transmission at the level of 95%. The X-ray diffraction studies as well as scanning electron microscopy images confirmed the chemical and structural compositions of the coatings. They are thermally stable at the temperature up to 250 °C. Moreover, the thermal analysis showed that the obtained composite material has greater thermal resistance than the pure nanotubes.

scholarly journals The Influence of A Mo Addition on the Interfacial Morphologies and Corrosion Resistances of Novel Fe-Cr-B Alloys Immersed in Molten Aluminum

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 256 ◽  
Author(s):  
Zicheng Ling ◽  
Weiping Chen ◽  
Weiye Xu ◽  
Xianman Zhang ◽  
Tiwen Lu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Probe ◽  
Molten Aluminum ◽  
Dendritic Structure ◽  
H13 Steel ◽  
X Ray ◽  
Transmission Electron ◽  
The Matrix ◽  
Scanning Electron

The influence of a Mo addition on the interfacial morphologies and corrosion resistances of novel Fe-Cr-B alloys in molten aluminum at 750 °C was systematically investigated using scanning electron microscopy, X-ray diffractometer, electron probe microanalysis, and transmission electron microscopy. The results indicated that Mo could not only strengthen the matrix but also facilitate the formation of borides. Furthermore, the microstructures of Mo-rich M2B boride changed from a local eutectic net-like structure to a typical coarse dendritic structure and a blocky hypereutectic structure with increasing Mo addition. This was true of the blocky Mo-rich M2B boride, rod-like Cr-rich M2B boride and the corrosion products, which had a synergistic effect on retarding of the diffusion of molten aluminum. Notably, the corrosion resistance of the Fe-Cr-B-Mo alloy, with an 8.3 wt.% Mo addition, was 3.8 times higher than that of H13 steel.

Scanning Electron Microscopy And Electron Probe Microanalysis Of Extraterrestrial Materials

1999 ◽  
Vol 5 (S2) ◽  
pp. 2-3
Author(s):  
J. I. Goldstein
Keyword(s):  
Electron Microscopy ◽  
Low Temperatures ◽  
Electron Probe ◽  
Iron Meteorite ◽  
The Moon ◽  
Iron Meteorites ◽  
Slow Cooling ◽  
Electron Probe Microanalyzer ◽  
Extraterrestrial Materials ◽  
Scanning Electron

One of the first samples analyzed by Castaing in his electron probe microanalyzer (EPMA) some 50 years ago was an iron meteorite. The Widmanstatten pattern microstructure of iron meteorites can be observed at very low magnifications ( Fig. 1). These meteorites are ideal samples for microanalysis because of the Ni gradient which extends over 10 to 1000 microns in the parent taenite phase of these Fe-Ni samples (Fig. 3). The Ni gradient is the result of very slow cooling of the iron meteorite, in terms of millions of years, within a parent'asteroid.The scanning electron microscope (SEM) has been used to characterize the microstructure of meteorites, as well as samples from the moon and mars. For example, the microstructure of the dark etching taenite areas (T in Fig. 1) of the Carleton iron meteorite is shown in Fig 2. In this example, precipitates are observed along original martensite laths which form during the cooling of the iron meteorite at low temperatures.

A comparative study of the morphology, chemical composition and weathering of rhyolitic and andesitic glass

Clay Minerals ◽  
1980 ◽  
Vol 15 (2) ◽  
pp. 165-173 ◽  
Author(s):  
J. H. Kirkman ◽  
W. J. McHardy
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
New Zealand ◽  
Chemical Composition ◽  
Electron Probe ◽  
Volcanic Glass ◽  
Chemical Activity ◽  
Rapid Rate ◽  
Bonding Characteristics ◽  
Scanning Electron

AbstractThe morphology of volcanic glass particles in rhyolitic and andesitic tephra of central North Island and Taranaki areas of New Zealand has been studied by scanning electron microscopy. Electron probe analyses of the glasses are compared with those of the clays to which they weather. Loss of silica characterizes the weathering of both glasses. The rapid rate of weathering of andesitic glass is attributed to its occurrence as fine, soft microlites and extensive substitution of Al for Si in the structure. Rhyolitic glass weathers more slowly because it occurs as hard and brittle particles containing relatively little alumina. It is suggested that the structure, chemical composition and chemical activity of allophane is governed largely by the chemical composition and bonding characteristics of the parent glass.

SiC Particles Concentration Dependent the Properties of Electroless Ni-P-SiC Coatings

2012 ◽  
Vol 457-458 ◽  
pp. 146-149
Author(s):  
Yan Hai Cheng ◽  
Shi Ju Zhang ◽  
Yu Xing Peng ◽  
Fang Fang Xing ◽  
Jie Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Particle Concentration ◽  
Composite Coatings ◽  
Sic Particles ◽  
Plating Solution ◽  
Electroless Ni ◽  
Sic Coatings ◽  
Scanning Electron ◽  
Sic Particle

In this study, Ni-P-SiC composite coatings were prepared by adding different amount of SiC particles into electroless Ni-P plating solution. The effects of SiC particles concentration in solution on depositing rate and composition of the coatings were investigated. The different SiC contents in coatings could be obtained by adjusting the amount of SiC particle concentration in electroless plating solution. Scanning electron microscopy (SEM) results indicate that SiC particles are dispersed in the composite coating and Ni-P alloy is mainly as a bond metal envelope with SiC particles. At the same time, the microhardness became increased and the wear resistance improved with the increasing of SiC content.

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