scholarly journals Determination of mechanical properties of coatings obtained by non-vacuum electron beam cladding

2019 ◽  
Vol 681 ◽  
pp. 012020
Author(s):  
T A Krylova ◽  
Yu A Chumakov
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Properties Of Coatings

Comparison of Microstructure and Mechanical Properties of Co-Based and Fe-Based Alloy Coatings Deposited by PTA

2013 ◽  
Vol 834-836 ◽  
pp. 617-622 ◽  
Author(s):  
Ming Lou ◽  
Yu Xiang Xu ◽  
Hong Wu Ouyang ◽  
Yong Du
Keyword(s):  
Mechanical Properties ◽  
Electron Probe ◽  
Optical Microscope ◽  
Properties Of Coatings ◽  
Composition Distribution ◽  
Stellite 6 ◽  
Plasma Transferred Arc ◽  
Scanning Electron Microcopy ◽  
Scanning Electron

Stellite 6 Co-based and Hӧganӓs Fe-based alloy coatings were deposited on austenitic engine valve using plasma transferred arc (PTA) hardfacing. The microstructures, composition distribution and mechanical properties of coatings were investigated by combining optical microscope (OM), scanning electron microcopy (SEM), field emission electron-probe analyzer (EPMA) and nanoindentation technique. The microstructures of hardfacing coatings consist of three phases which belong to hypoeutectic structure and Co-based coating has more uniformed and regularly changed microstructure. The determination of mechanical properties reveals that Co-based coating attains higher hardness value (~5.229 GPa), H/E (0.0265) and H3/E*2 (0.00323) than that of Fe-based coating, signified better wear resistance property.

Effects of Surface Contamination Layers and Roughness on the Determination of Mechanical Properties of Thin Films Using Nanoindentation

2011 ◽  
Author(s):  
Nicholaos G. Demas ◽  
Oyelayo O. Ajayi ◽  
Iqbal Shareef
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Surface Roughness ◽  
Statistical Analysis ◽  
Surface Contamination ◽  
Properties Of Coatings ◽  
Simple Method ◽  
Nanomechanical Properties ◽  
Steel Substrates

Nanoindentation measurements on TiAlN, CrN, a-C:H:Me, and TiN, deposited on steel substrates have been performed. It was found that the resulting surface roughness/morphology after deposition significantly affects the measurements of nanomechanical properties, while measurements of these properties on the surface may be significantly different than the bulk portion of the coating, exhibiting a lower nanohardness due to the existence of a surface contamination layer. A simple method is proposed for accurately measuring the nanomechanical properties of coatings alleviating the need for excessive statistical analysis and the issues that arise from surface topography and the presence of surface and contamination layers on thin films.

INFLUENCE OF PHASE STRUCTURE POLYMERIC FILMFORMER ON PHYSICAL MECHANICAL AND WATER RESISTANT PROPERTIES OF COATINGS

2021 ◽  
pp. 87-96
Author(s):  
V.A. Kuznetsova ◽  
◽  
E.V. Kurshev ◽  
A.A. Silaeva ◽  
S.A. Marchenko ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Phase Structure ◽  
Water Resistance ◽  
Polymeric System ◽  
Properties Of Coatings ◽  
Organic Silicon ◽  
Curing Agents ◽  
Modified Epoxy

The phase structure, adhesion and physical mechanical properties, water resistance of varnish coatings on the basis of the modified and not modified epoxy filmformers, with organic silicon ammine «AСOT-2» and low-molecular «ПO-200» polyamide as curing agents. It is established that the process of structurization of unfilled epoxy compositions depends on each component of polymeric system. The received results of determination of adhesion, physical mechanical properties, water resistance correlate with results of researches of phase structure of the coatings received on the basis of modified and not modified epoxy compositions, with organic silicon ammine «AСOT-2» and low-molecular «ПO-200» polyamide as curing agents.

The control and optimization of the curing process of epoxy coatings: a case of poly(glycidoxy siloxane) resins

2016 ◽  
Vol 36 (8) ◽  
pp. 819-827
Author(s):  
Tomasz Jeliński ◽  
Piotr Cysewski ◽  
Edwin Makarewicz
Keyword(s):  
Mechanical Properties ◽  
Degree Of Crystallinity ◽  
Curing Process ◽  
Technological Parameters ◽  
Properties Of Coatings ◽  
Important Indicator ◽  
Curing Conditions ◽  
Amine Curing Agent ◽  
Amine Curing

Abstract Coatings from poly(glycidoxy siloxane) resins were developed and their mechanical properties examined. Three different resins with varying numbers of methyl siloxane and glycidyl siloxane units were tested. Crystallinity was found to be a very important indicator of the mechanical properties of coatings, as the parameters such as cupping and hardness were linearly dependent on the degree of crystallinity of coatings. The method involving the spectrophotometric determination of unbounded amine curing agent was successfully applied as a way of optimizing the curing process both for expected mechanical properties and for ecological aspect. It was found that the resin with 50 methyl siloxane and 25 glycidyl siloxane units was the most appropriate for technological use because of the preferred mechanical properties and stability of technological parameters. Interestingly, this type of resin was characterized by the lowest degree of crystallinity. The curing conditions leading to the optimal product corresponded to 30 min of curing at 120°C or 20 min at 140°C. Under such conditions, the amount of released unbounded amine was the lowest. It was also found that poly(glycidoxy) siloxane resins may be ecologically valuable since the release of amine from this type of resins is smaller than that from a typical epoxy resin.

The Analysis of Dislocations Using a Symmetry Criterion

1972 ◽  
Vol 30 ◽  
pp. 660-661
Author(s):  
J. C. Ingram ◽  
P. R. Strutt ◽  
Wen-Shian Tzeng
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Displacement Field ◽  
Standard Technique ◽  
Residual Image ◽  
Symmetry Criterion

The invisibility criterion which is the standard technique for determining the nature of dislocations seen in the electron microscope can at times lead to erroneous results or at best cause confusion in many cases since the dislocation can still show a residual image if the term is non-zero, or if the edge and screw displacements are anisotropically coupled, or if the dislocation has a mixed character. The symmetry criterion discussed below can be used in conjunction with and in some cases supersede the invisibility criterion for obtaining a valid determination of the nature of the dislocation.The symmetry criterion is based upon the well-known fact that a dislocation, because of the symmetric nature of its displacement field, can show a symmetric image when the dislocation is correctly oriented with respect to the electron beam.

Enhanced information from biological materials through technological improvements in cryo-electron microscopy

1992 ◽  
Vol 50 (1) ◽  
pp. 788-789
Author(s):  
Marc J.C. de Jong ◽  
Wim M. Busing ◽  
Max T. Otten
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Biological Materials ◽  
Electron Crystallography ◽  
Cryo Electron Microscopy ◽  
Transmission Electron ◽  
The Many ◽  
Technological Improvements ◽  
Beam Damage

Biological materials damage rapidly in the electron beam, limiting the amount of information that can be obtained in the transmission electron microscope. The discovery that observation at cryo temperatures strongly reduces beam damage (in addition to making it unnecessaiy to use chemical fixatives, dehydration agents and stains, which introduce artefacts) has given an important step forward to preserving the ‘live’ situation and makes it possible to study the relation between function, chemical composition and morphology.Among the many cryo-applications, the most challenging is perhaps the determination of the atomic structure. Henderson and co-workers were able to determine the structure of the purple membrane by electron crystallography, providing an understanding of the membrane's working as a proton pump. As far as understood at present, the main stumbling block in achieving high resolution appears to be a random movement of atoms or molecules in the specimen within a fraction of a second after exposure to the electron beam, which destroys the highest-resolution detail sought.

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