scholarly journals Plasma Spray Coatings of Natural Ores From Structural, Mechanical, Thermal, and Dielectric Viewpoints

Coatings ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 3 ◽  
Author(s):  
Pavel Ctibor ◽  
Barbara Nevrlá ◽  
Karel Neufuss ◽  
Jan Petrášek ◽  
Josef Sedláček
Keyword(s):  
Optical Materials ◽  
Low Loss ◽  
Plasma System ◽  
Dielectric Characteristics ◽  
Spray Coatings ◽  
Thermal Barriers ◽  
Plasma Spray Coatings ◽  
High Feed ◽  
Medium Quality ◽  
Plasma Sprayed

Various natural materials, namely ilmenite, diopside, tourmaline, olivine, garnet, and basalt, were plasma-sprayed and analyzed. This paper summarizes the various achievements of our earlier research and adds new results—mainly dielectric and optical characterizations. Plasma spraying of all of the materials was rather easy with a high feed-rate plasma system, which could process many kilograms of powder per hour. For easier characterizations, the coatings were detached from substrates in order to remain self-supporting. The plasma-sprayed layers that were coated from all studied materials acted as medium-permittivity and low-loss dielectrics, antireflective optical materials, and medium quality anti-abrasive barriers. Phase composition and microhardness were evaluated in addition to microstructure observations. Some coatings were amorphous and crystallized after further heating. As the melting points were well above 1000 °C, all of them could also serve as thermal barriers for aluminum alloys and similar metals. The only material that was not easily sprayed was tourmaline, which gave very porous coatings without environmental barrier or dielectric characteristics.

Surface Morphology of Plasma Sprayed Ceramic Coatings

1998 ◽  
Author(s):  
S. Oki ◽  
S. Gohda ◽  
M. Yamakawa
Keyword(s):  
Surface Morphology ◽  
Ceramic Coatings ◽  
Detailed Knowledge ◽  
Preparation Methods ◽  
Spray Coatings ◽  
Polished Cross Section ◽  
Plasma Spray Coatings ◽  
Coating Formation ◽  
Plasma Sprayed

Abstract A novel method for characterization of microstructure of coatings is presented. Properties of plasma spray coatings are affected by their microstructure, which depends on the spraying conditions. Therefore, a detailed knowledge of microstructure is very important in order to know the coating formation mechanism and the properties of the coatings. There are many studies to characterize the microstructure of coatings. In most of those studies, the microstructures are characterized from the polished cross-section of the coatings, and the results strongly depend on the preparation methods. In this study, a new method for the characterization of coating microstructures by means of surface morphology is proposed. The distribution of shape and dimensions of splats were examined using quantitative analysis of scanning electron microscope images from the surface of the coatings. The results indicate that the surface morphology strongly depends on the spraying conditions.

scholarly journals The History, Technical Specifications and Efficacy of Plasma Spray Coatings Applied to Joint Replacement Prostheses

2016 ◽  
Vol 6 (4) ◽  
Author(s):  
Andrew McCabe ◽  
Martin Pickford ◽  
James Shawcross
Keyword(s):  
Plasma Spray ◽  
Thermal Plasma ◽  
Clinical Performance ◽  
Pure Titanium ◽  
Subsequent Development ◽  
Implantable Medical Devices ◽  
Spray Coatings ◽  
Plasma Spray Coatings ◽  
Technical Specifications ◽  
Plasma Sprayed

Thermal plasma sprayed coatings are designed to improve both the biocompatibility and durability of implantable medical devices, and include pure titanium, cobalt/chrome alloy and hydroxyapatite.  Coated joint replacements have now been in continuous clinical use for thirty years and are applied to products manufactured or used in Europe, North America, South America, Africa, Asia and Australasia. Prostheses incorporating such coatings have been successfully implanted into several million of patients worldwide and to date there have been very few reports of any failure of an implant which could be attributed to problems with, or failure of, the coating. This paper summarises the early history of cementless prostheses and subsequent development, specification, validation, regulatory requirements and clinical performance of thermal plasma spray coatings provided by Accentus Medical.

Microstructure and Properties of Plasma Spray Coatings Prepared from Ti-Zr-Ni Quasicrystalline Powders

2007 ◽  
Vol 534-536 ◽  
pp. 89-92 ◽  
Author(s):  
Hyun Kwang Seok ◽  
Yu Chan Kim ◽  
Frédéric Prima ◽  
Eric Fleury
Keyword(s):  
Plasma Spray ◽  
Volume Fraction ◽  
Icosahedral Phase ◽  
Vacuum Plasma Spray ◽  
Laves Phases ◽  
Electrochemical Tests ◽  
Spray Coatings ◽  
Plasma Spray Coatings ◽  
Zro2 Phase ◽  
Coating Layers

This works deals with the deposition of Ti-Zr-Ni icosahedral quasicrystalline powders by low vacuum plasma spray technique and the performances of the resulting coating layers. The microstructure of the coatings, as analyzed by X-ray diffraction and TEM techniques, consisted of nanometer-sized W-Ti50Zr35Ni15 1/1 cubic approximant and TiZrNi Laves phases as well as a low volume fraction of submicrometer-sized ZrO2 phase. The absence of the icosahedral phase in the coating layers was explained by the loss of Ti during plasma spraying. The shift in the composition and the presence of the ZrO2 phase within the coating layers are believed to be responsible for the reduced microhardness and corrosion performances evaluated by electrochemical tests in a Hanks’ Balance Salt Solution at 37oC.

Use of Different Process Gases for Manufacturing Isolating Alumina Coatings by Flame Spraying with Cords

2021 ◽  
Author(s):  
M. Hauer ◽  
M. Meyer ◽  
D. Billieres ◽  
C. Bricquet ◽  
F. Gerstgrasser ◽  
...  
Keyword(s):  
Volume Resistivity ◽  
Alpha Phase ◽  
Flame Spraying ◽  
Flame Spray ◽  
Alumina Coatings ◽  
Spray Coatings ◽  
Aluminum Hydroxides ◽  
Fine Microstructure ◽  
Plasma Sprayed ◽  
Aluminum Substrates

Abstract This study assesses the quality of flame-sprayed alumina coatings produced from recently developed alumina cord using argon and compressed air as atomizing gases. Coatings of different thicknesses were deposited on aluminum substrates and then analyzed using optical microscopy, X-ray diffraction, and resistivity measurements. The coatings, particularly those sprayed with argon, had fine microstructure and higher surface and volume resistivity than flame-spray coatings made from alumina cord in the past. They were also found to have higher alpha phase content than plasma-sprayed coatings, regardless of the atomizing gas used. The effect of humidity and the possible formation of aluminum hydroxides are also addressed.

Pressure-Based Liquid Feed System for Suspension Plasma Spray Coatings

2011 ◽  
Vol 20 (4) ◽  
pp. 967-973 ◽  
Author(s):  
Elliot M. Cotler ◽  
Dianying Chen ◽  
Ronald J. Molz
Keyword(s):  
Plasma Spray ◽  
Suspension Plasma Spray ◽  
Feed System ◽  
Spray Coatings ◽  
Plasma Spray Coatings ◽  
Liquid Feed

New Developments in Multiple Small-Angle Neutron Scattering Studies of Advanced Ceramics

1994 ◽  
Vol 376 ◽  
Author(s):  
Andrew J. Allen ◽  
Norman F. Berk ◽  
Susan Krueger ◽  
Gabrielle G. Long ◽  
Helen M. Kerch ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Microstructural Characterization ◽  
Porous Ceramics ◽  
Single Scattering ◽  
Previous Method ◽  
Silica Gels ◽  
Spray Coatings ◽  
Plasma Spray Coatings

ABSTRACTAn enhanced multiple small-angle neutron scattering (MSANS) formulation has been developed to interpret the beam-broadening, arising from coarse, concentrated pore/grain microstructures in porous ceramics and similar materials. Prolific scattering from such systems precludes single-scattering studies (apart from Porod surface determinations). Previous MSANS techniques, which have been developed to extract the mean pore dimensions, either treat a range of scattering morphologies, while assuming that the scattering is in the diffraction limit, or they consider refraction effects, while assuming that the scattering features are spherical. Many systems of interest violate both these assumptions. In the enhanced formulation, the previous method, which allowed fully for refraction, is extended to non-spherical scattering morphologies. Applications of the MSANS formulation to sintering studies of Si3N4 and silica gels, and to the microstructural characterization of plasma-spray coatings are currently of interest.

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