AEM Characterization of Particles in Electrodeposited Chromium Plates

1990 ◽  
Vol 48 (2) ◽  
pp. 46-47
Author(s):  
Li Chang ◽  
Rung-Ywan Tsai ◽  
Shinn-Tyan Wu
Keyword(s):  
Electron Microscopy ◽  
Surface Hardening ◽  
Steel Surface ◽  
Direct Evidence ◽  
Steel Substrate ◽  
Carbon Steels ◽  
The Past ◽  
Standard Solution ◽  
A Current

Electrodeposited Cr plating has been used for steel surface hardening since 1930. It is well known that there are particles precipitated during annealing the plate. However, no direct evidence has been shown to identify the species of the particles. Despite several microstructural characterizations having been carried out about thirty years ago it is surprised that no research has been done yet for the past decade to take the advantage of the powerful strength of modern electron microscopy. The present work reports the identification of the particles on the basis of AEM study.Cr plates were deposited on plain carbon steels by conventional method using a standard solution containing CrO3 250 g/l and H2SO4 2.5 g/l at a current density 40 A/dm2 and 45°C. The plates of 0.1mm thickness were then stripped off from steel substrate by dilute HNO3 before annealing was carried out in vacuum at 600,700, and 800°C for 1 to 6 hours.

Electron Microscope Characterization of Pulse Annealed Semiconductors

1980 ◽  
Vol 2 ◽  
Author(s):  
A. G. CULLIS
Keyword(s):  
Electron Microscopy ◽  
Defect Structure ◽  
Device Fabrication ◽  
Fabrication Technology ◽  
The Past ◽  
Semiconductor Structures ◽  
Pulse Processing ◽  
Processing Techniques

ABSTRACTThe pulse processing techniques that have assumed prominence over the past few years offer various important advantages for device fabrication technology. However, the usefulness of each individual method depends substantially upon the specific annealing mechanism involved. This article demonstrates the role of electron microscopy in elucidating such mechanisms and in analysing annealed semiconductor structures of importance to both research workers and semiconductor technologists. The range of laser and electron beam pulse annealing methods is covered and defect structure transitions observed are related to the solid and liquid phase processes occurring. Characteristic impurity trapping and segregation phenomena are described.

Microstructure and Hardness Characterization of a NiCr/Cr3C2 Coating by High-Velocity Oxy-Fuel Thermal Spraying

2009 ◽  
Vol 79-82 ◽  
pp. 397-400
Author(s):  
Yu Ping Wu ◽  
Gai Ye Li
Keyword(s):  
Electron Microscopy ◽  
Stainless Steel ◽  
High Velocity ◽  
Steel Substrate ◽  
Thermal Spraying ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Hvof Thermal Spraying

A NiCr/Cr3C2 composite coating with a thickness of approximately 200 m was deposited onto 1Cr18Ni9Ti stainless steel substrate by high-velocity oxy-fuel (HVOF) thermal spraying. Microstructure of the coating was characterized using X-ray diffraction(XRD), scanning electron microscopy(SEM) and transmission electron microscopy (TEM). The coating comprised a NiCr matrix and two types of carbides. The NiCr matrix was composed of an amorphous phase and nanocrystalline grain with a size of 10–50 nm. The microhardness of the coating was found to be 1200Hv, which is significantly greater than that of the stainless steel (1Cr18Ni9Ti) substrate (285 Hv).

Direct Evidence of Surface Roughness in Small Metallic Particles

1994 ◽  
Vol 368 ◽  
Author(s):  
Miguel Jose Yacaman ◽  
Samuel Tehuacanero ◽  
Cristina Zorrilla ◽  
Gabriela Diaz
Keyword(s):  
Electron Microscopy ◽  
Image Processing ◽  
Surface Roughness ◽  
Direct Evidence ◽  
High Resolution Electron Microscopy ◽  
Detailed Structure ◽  
Metallic Particles ◽  
New Information ◽  
Resolution Electron

ABSTRACTThe characterization of nanoparticles is of prime importance in catalysis. High Resolution Electron Microscopy coupled with image processing has produce a lot of new information on the detailed structure of the particles. In this paper we discuss the possibility of applying these techniques to the study of surface roughness.

scholarly journals Liquid electron microscopy: then, now and future

2019 ◽  
Vol 49 (1) ◽  
Author(s):  
Anahita Vispi Bharda ◽  
Hyun Suk Jung
Keyword(s):  
Electron Microscopy ◽  
Functional Characterization ◽  
Analytical Tool ◽  
Electron Microscopic ◽  
Liquid Environment ◽  
Microscopic Imaging ◽  
The Past ◽  
Technical Developments ◽  
Comprehensive Framework

Abstract Contemporary microscopic imaging at near-atomic resolution of diverse embodiments in liquid environment has gained keen interest. In particular, Electron Microscopy (EM) can provide comprehensive framework on the structural and functional characterization of samples in liquid phase. In the past few decades, liquid based electron microscopic modalities have developed tremendously to provide insights into various backgrounds like biological, chemical, nanoparticle and material researches. It serves to be a promising analytical tool in deciphering unique insights from solvated systems. Here, the basics of liquid electron microscopy with few examples of its applications are summarized in brief. The technical developments made so far and its preference over other approaches is shortly presented. Finally, the experimental limitations and an outlook on the future technical advancement for liquid EM have been discussed.

Wear Characterization of Thermal Sprayed and Fused Fe-Ni-Cr Alloy Coatings with the Addition of CeO2

2011 ◽  
Vol 239-242 ◽  
pp. 35-38
Author(s):  
Zhen Yu Zhang ◽  
Biao Chen ◽  
Bu Nv Liang ◽  
Peng Lin Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Steel Substrate ◽  
Sliding Speed ◽  
Worn Surface ◽  
Oxidation Wear ◽  
Wear Tests ◽  
Oxide Debris ◽  
Scanning Electron

Fe-Ni-Cr alloy powders with CeO2 were flame sprayed and fused on the surface of 1045 carbon steel substrate. The effect of CeO2 on microstructure and tribological behavior of coatings were studied experimentally by means of scanning electron microscopy (SEM), field emission gun scanning electron microscopy (FEGSEM), energy dispersive spectroscopy (EDS) and wear tests. The results show that an adhered oxide debris layer was formed on the worn surface in friction which contributed to decreased wear. Wear rate of the material increased with the load, but dramatically decreased at first and then slightly decreased the sliding speed. The friction coefficient of the material decreased slightly with the load, but increased with sliding speed at first, and then tended to be a constant value. Wear mechanism of the coatings was oxidation wear and a large amount of counterpart material was transferred to the coatings, the RE oxide in the debris layer contributes to the improvement in wear resistance.

Linear Defects Generated by Inclusion of Hydrogen in Nickel Electrodeposit

1976 ◽  
Vol 34 ◽  
pp. 642-643
Author(s):  
S. Nakahara
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Structural Characterization ◽  
Nickel Film ◽  
Ofhc Copper ◽  
Linear Defects ◽  
Transmission Electron ◽  
A Current ◽  
Nickel Electrodeposit

During the course of structural characterization of nickel electrodeposit, we have found that there are a large number of linear defects which are different from dislocations. This communication reports a detailed analysis of these defects using transmission electron microscopy.Nickel film was prepared by electrodeposition from a bath containing 0.43 M NiSO4-6H2O and 0.5 M H3BO3. The pH of the bath was adjusted to 1.5. A sheet of annealed OFHC copper was used as the substrate. All the platings were carried out at 30°C.Nickel film plated at a current density of 5 MA/cm2 contained these linear Refects. Figures l(a), (b), and (c) show micrographs of the film taken with g = 200, 220, and 131, respectively. The images of the defects are indicated by four fine arrows in Fig. 1(c). They were not easily discernible with low-order g's such as 111, 200, and 220 (see Figs. 1(a) and (b)).

Rust exfoliation on carbon steels in chloride-rich atmospheres

2015 ◽  
Vol 33 (5) ◽  
pp. 263-282 ◽  
Author(s):  
Belen Chico ◽  
Jenifer Alcántara ◽  
Elizabeth Pino ◽  
Iván Díaz ◽  
Joaquín Simancas ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Steel Substrate ◽  
Decisive Role ◽  
Chloride Ion ◽  
Carbon Steels ◽  
Metallic Surface ◽  
Weathering Steel ◽  
Deposition Rates ◽  
X Ray ◽  
Transmission Electron

AbstractThe exposure of carbon steel in marine atmospheres can lead in certain circumstances to the formation of thick rust layers (containing a number of compact laminas) that are easily detached (exfoliated) from the steel substrate, leaving it unprotected and considerably accelerating the corrosion process. This deterioration phenomenon is of particular concern in steel infrastructures located close to the sea (civil constructions, bridges, etc.), whose service lifetime can be extraordinarily limited. High times of wetness of the metallic surface and high chloride ion deposition rates play a decisive role in the formation of this type of rust. Research has been carried out for 1 year in eight pure marine atmospheres with annual average chloride deposition rates of 70–1906 mg Cl-/m2 day. The studied carbon steels consisted of one mild steel, one conventional weathering steel (Corten A), and one high nickel (~3 wt.%) advanced weathering steel (AWS). The paper describes the environmental conditions that lead to the formation of these thick multilaminar rust layers and presents a characterisation study of this singular type of rust using a variety of analysis techniques: scanning electron microscopy/energy-dispersive X-ray spectroscopy, X-ray diffraction, Mössbauer spectroscopy, and transmission electron microscopy/electron diffraction. The Ni-AWS shows greater resistance to the occurrence of rust exfoliation.

Microstructural Evaluation of Annealed Low-Alloy Carbon Steels with the Magnetic Barkhausen Noise

2015 ◽  
Vol 644 ◽  
pp. 258-261
Author(s):  
Nikolaos Philopimin Kanellopoulos
Keyword(s):  
Electron Microscopy ◽  
Carbon Steels ◽  
Barkhausen Noise ◽  
Magnetic Barkhausen Noise ◽  
Microstructural Evaluation ◽  
Alloy Carbon ◽  
Aisi 4130 ◽  
Nondestructive Characterization ◽  
Scanning Electron

The present paper investigates the utilization of the MBN method for the nondestructive characterization of annealed AISI 4130 steel samples. The resulting magnetic properties were further evaluated by examining the microstructure of the annealed samples by using scanning electron microscopy.

scholarly journals EFFECT OF TiO2 NANOPARTICLES ON THE MECHANICAL AND ANTICORROSIVE PROPERTIES OF Zn-Ni COMPOSITE COATINGS

2019 ◽  
Vol 25 (2) ◽  
pp. 107
Author(s):  
Nadjette Belhamra ◽  
Abd Raouf Boulebtina ◽  
Okba Belahssen
Keyword(s):  
Electron Microscopy ◽  
Structural Characteristics ◽  
Steel Substrate ◽  
Composite Coatings ◽  
Film Surface ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron ◽  
Mild Steel Substrate

<p class="AMSmaintext1"><span lang="EN-GB">In this paper, we are interested in the study of electrochemical, morphological and structural characteristics of the properties of the deposits of Zn-Ni-TiO<sub>2</sub> obtained by electrodeposition on the mild steel substrate in a bath of sulfate. The principal aim is to improve the coatings with better properties, by incorporation of titanium oxide, which is a hard compound, chemically stable and irreducible. The characterization of the coatings was carried out by scanning electron microscopy (SEM) and by X-ray diffraction. The morphology of the film surface varies with the concentration of oxide titanium and it was found higher values of microhardness. Electrochemical characterization of the composites had been carried out through potentiodynamic polarization. The results showed that better corrosion resistance with the incorporation of oxide titanium.</span></p>

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