scholarly journals Gas Evolution Rates of Graphite Protective Coatings in Dependence on the Applied Solvent and Kind of Atmosphere

2016 ◽  
Vol 61 (4) ◽  
pp. 2129-2134
Author(s):  
A. Kmita ◽  
D. Drożyński ◽  
J. Mocek ◽  
A. Roczniak ◽  
J. Zych ◽  
...  
Keyword(s):  
Liquid Metal ◽  
Protective Coating ◽  
Protective Coatings ◽  
Measuring Method ◽  
Gas Evolution ◽  
Casting Method ◽  
Air Atmosphere ◽  
Two Systems ◽  
Mould Cavity

Abstract The results concerning emission of gases from two commercial graphite protective coatings for moulds and cores (water and alcoholic) are given in the hereby paper. Investigations were performed in two systems. One of the systems was corresponding to conditions occurring inside the mould cavity immediately after its pouring with liquid metal (Method 1), while the second was simulating conditions deep inside the mould at a certain distance from the casting (Method 2). Investigations were carried out in the CO2 atmosphere and in the air. The water protective coating generated 1.5 to 3 times larger volume of gases than the alcoholic coating (in dependence on the measuring method and atmosphere). The smallest differences occurred in the air atmosphere, while the largest in the CO2 atmosphere.

Assessment of Damage from Organic Protective Coating Treatments to Historic Stone Buildings and Sculptures

2010 ◽  
Vol 44-47 ◽  
pp. 610-613
Author(s):  
Qiang Liu ◽  
Bing Jian Zhang
Keyword(s):  
Protective Coating ◽  
Side Effect ◽  
Protective Coatings ◽  
Organic Coating ◽  
Stone Conservation ◽  
Silicon Compounds ◽  
Artificial Weathering ◽  
Organic Silicon ◽  
Destruction Mechanism ◽  
Historic Stone

The conservation of historic stone buildings and sculptures is receiving growing attention because of weathering. Now, the techniques for stone conservation are primarily achieved through the use of organic coating treatments. Although some defects of organic protective materials have been recognized, the further shortcoming is still short of awareness. Here we show our investigations of the side effect of organic coating treatments. Some kinds of common stones, including sandstone, tuff, granite, dolomite and marble, were selected as protected objects. Organic silicon compounds were used as protective coatings. The artificial weathering, including salting, freezing and heating, was designed. The treated stones’ decaying was investigated. The results reveal that the treated stone decaying is aggravated. Moreover, the destruction mechanism has been discussed.

scholarly journals Deposition of SiOxCyHz Protective Coatings on Polymer Substrates in an Industrial-Scale PECVD Reactor

Coatings ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 234 ◽  
Author(s):  
Žiga Gosar ◽  
Janez Kovač ◽  
Miran Mozetič ◽  
Gregor Primc ◽  
Alenka Vesel ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Protective Coating ◽  
Photoelectron Spectroscopy ◽  
Secondary Ion Mass Spectrometry ◽  
Protective Coatings ◽  
Plasma Reactor ◽  
Chemical Vapour ◽  
Rf Discharge ◽  
Average Roughness ◽  
Polymer Substrates

The deposition of protective coatings on aluminised polymer substrates by a plasma enhanced chemical vapour deposition PECVD technique in a plasma reactor with a volume of 5 m3 was studied. HMDSO was used as a precursor. Plasma was sustained in a capacitively coupled radiofrequency (RF) discharge powered by an RF generator operating at 40 kHz and having an adjustable output power up to 8 kW. Gaseous plasma was characterised by residual gas mass spectrometry and optical emission spectroscopy. Polymer samples with an average roughness of approximately 5 nm were mounted into the plasma reactor and subjected to a protocol for activation, metallisation and deposition of the protective coating. After depositing the protective coating, the samples were characterised by secondary ion mass spectrometry (SIMS) and X-ray photoelectron spectroscopy (XPS). The combination of various techniques for plasma and coating characterisation provided insight into the complex gas-phase and surface reactions upon deposition of the protective coatings in the industrial-size plasma reactor.

Hot Corrosion Resistance Properties of Al-Si Coatings Obtained by Slurry Method

2012 ◽  
Vol 326-328 ◽  
pp. 273-278 ◽  
Author(s):  
Agnieszka Kochmańska
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Hot Corrosion ◽  
Protective Coatings ◽  
Cast Steel ◽  
High Temperature Corrosion ◽  
Air Atmosphere ◽  
Before And After ◽  
Slurry Method ◽  
Thermal Shocks

This paper presents the results of research on aluminide protective coatings manufactured on hightemperature creep resistant cast steel. The main purpose of these coatings is protection against the high temperature corrosion, at carburizing and oxidizing potential atmosphere. Coatings were obtained on cast steel type GXNiCrSi 3018 by slurry cementation in air atmosphere. The tests of carburizing and oxidizing were carried out. The structure of the coatings before and after carburizing and oxidizing is described in the present paper. The chemical composition, thickness and microstructure of coatings were determined. These coatings could protect equipment against hot corrosion at carburizing and oxidizing atmosphere and have thermal shocks resistance.

scholarly journals Comparative Evaluation of effect of resin protective coatings on the surface hardness and shear punch strength of different GlCs - An InVitro Study

2021 ◽  
Vol 19 (3) ◽  
pp. 160-165
Author(s):  
N. Mishra ◽  
M. Agarwal ◽  
M. P. Singh ◽  
A. Khullar ◽  
K. Magwa ◽  
...  
Keyword(s):  
Shear Strength ◽  
Clinical Practice ◽  
Protective Coating ◽  
Surface Coating ◽  
Comparative Evaluation ◽  
Protective Coatings ◽  
Surface Hardness ◽  
Daily Clinical Practice ◽  
Glass Ionomer ◽  
Shear Punch

G-Coat Plus is a nano-filled, self-adhesive light cured protective coating that strengthens, protects and enhances glass ionomer restorations. The effect of G- Coat plus on different GICs have not been studied comprehensively. Hence the study was conducted to compare the effect of resin coating on surface hardness and Shear punch strength of newer modified GIC.Materials and methods: 120 samples of three GICs i.e. Fuji IX Extra, Fuji IX Fast, Fuji II LC were prepared using specialized metal moulds. Specimens of Fuji II LC were light cured for 20 seconds. Coated and uncoated samples were tested for surface hardness and 30 samples were tested for shear punch strength. P < 0.05 was considered as significant. Results: Shear Punch Strength after G-Coat plus coating was significantly higher for Fuji IX Extra followed by Fuji II LC. Surface Hardness after G- Coat plus coating was significantly higher for Fuji IX Extra followed by Fuji IX Fast and Fuji II LC.Conclusion: Surface coating by a resin agent significantly increases the surface hardness and shear strength of the GIC. Considering the above stated findings, they can be incorporated into daily clinical practice to enhance the strength and longevity of GIC.

scholarly journals Sulfidation-Oxidation Resistance of Thermal Diffusion Multi-Layered Coatings on Steels

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5724
Author(s):  
Tomasz P. Dudziak ◽  
Ewa Rząd ◽  
Eugene Medvedovski ◽  
Gerardo Leal Mendoza
Keyword(s):  
Thermal Diffusion ◽  
316L Stainless Steel ◽  
Complex Shape ◽  
Protective Coatings ◽  
Diffusion Coatings ◽  
Air Atmosphere ◽  
Layered Coatings ◽  
Minimal Rate ◽  
High Degree ◽  
Layered Architectures

The high-temperature sulfidation-oxidation corrosion resistance of protective coatings deposited on carbon and 316L steels was studied. The coatings obtained via the thermal diffusion process had multi-layered architectures and consisted of aluminides, iron borides, or iron boride–TiO2 layers. The protective coatings experienced a minimal rate of mass changes, insignificant scale formation, and no delamination and surface micro-cracking after 504 h of exposure in 1% (Vol.) H2S-air atmosphere at 500 °C. Furthermore, the coatings demonstrated a high degree of integrity compared to bare 316L stainless steel. Aluminized steels demonstrated the highest performance among the studied materials. The developed thermal diffusion coatings are promising candidates due to their enhanced stability in H2S–air atmosphere; they may be employed for protection of inner and outer surfaces of long tubing and complex shape components.

Protective Coating Based on Siloxane Polymer Nanopatterned by Alkoxytitanate

2019 ◽  
Vol 945 ◽  
pp. 718-723 ◽  
Author(s):  
V.Y. Chukhlanov ◽  
O.G. Selivanov ◽  
N.V. Chukhlanova
Keyword(s):  
Protective Coating ◽  
Negative Impact ◽  
Protective Coatings ◽  
Anthropogenic Factors ◽  
Adhesive Properties ◽  
Atomic Force ◽  
Surface Nanostructure ◽  
Siloxane Polymer ◽  
20 Nm ◽  
The Impact

The paper considers the problems of creating new protective coatings based on organosilicon polymer – polymethylphenylsiloxane, modified with tetraisopropyltitanate. The mechanisms of siloxane polymer nanostructuring have been suggested. The coating surface nanostructure and the impact of material components content and nature on its properties have been studied. To research protective surface nanostructure, the method of atomic-force probe microscopy applying IntegraAura device has been used. Nanoparticles formations with 10-20 nm effective scale have been revealed. Adhesive properties of the protective coating have been studied. Glass and metal adhesion was determined applying the method of detachment from the steel discs substrate using adhesive meter PSO-MG4. The modification was stated not to cause any substantial loss of coating adhesive properties. Simultaneously modification process was accompanied with the increase of relative coating firmness.The developed compounds and corresponding coatings are aimed at protecting buildings and constructions against negative impact of natural and anthropogenic factors.

scholarly journals Physical modelling of the motion of a liquid metal melt along the surface of a heated rod

2019 ◽  
Vol 196 ◽  
pp. 00009 ◽  
Author(s):  
Pavel D. Lobanov ◽  
Eduard V. Usov ◽  
Ilya A. Klimonov ◽  
Alexander E. Kutlimetov ◽  
Anton A. Butov ◽  
...  
Keyword(s):  
Liquid Metal ◽  
Test Section ◽  
High Speed ◽  
Physical Modelling ◽  
Quartz Tube ◽  
Melt Flow ◽  
Metal Melt ◽  
High Speed Video ◽  
Air Atmosphere ◽  
Droplet Movement

The investigation of the melt flow of a liquid metal along the surface of a heated rod is carried up. In the experiments, the metal from the upper volume was drained over the surface of a quartz tube, heated from the inside. This pipe is used to simulate a fuel column. A high-speed video of the process was produced. Data are obtained on the features of the flow of a metal melt. The stages of formation of droplets are shown. The data on the shape and velocity of the droplet movement are given. It is shown that in the air atmosphere around the test section when the first drop passes on the surface of quartz, a trace is formed, along which the metal moves in the future. Direct and curvilinear rivulet flows on the rod's surface are also observed.

Ultrasonic measuring method for spraying thickness of protective coating on steel structure

2021 ◽  
Author(s):  
Zhigang Wang ◽  
Haitao Wang ◽  
Dexiu Dong ◽  
Jiahui Sheng ◽  
Qiufeng Li ◽  
...  
Keyword(s):  
Protective Coating ◽  
Steel Structure ◽  
Measuring Method ◽  
Ultrasonic Measuring

New Powdered Silicide Materials for Thermal Spraying Process and Coatings on the Niobium Base Alloys

1998 ◽  
Author(s):  
V. Terentieva ◽  
O. Bogatchkova ◽  
D. Cornu
Keyword(s):  
Protective Coating ◽  
Protective Coatings ◽  
Thermal Spraying ◽  
Base Material ◽  
Theory And Practice ◽  
Powder Materials ◽  
Self Healing ◽  
High Enthalpy ◽  
Boride Phases ◽  
Spraying Process

Abstract The given article presents some results of the scientific research devoted to the development of a new class of scale-resistant powder materials of the Si-Ti-Mo-B system for thermal spraying and using these materials for the creation of heat-resistant coatings on the niobium base alloys by means of various methods of thermal spraying. Also under consideration are problems relating to the theory and practice of obtaining reliable protective coatings on high-melting metals and their alloys, niobium ones included, intended for operation in high-enthalpy oxygen-containing gas flows. Hazard in commencing an oxidation reaction of the base material under coating is connected with density of open pores and cracks, and partial pressure of the oxidizer. Powdered multicomponent heterophase materials for gas-thermal spraying of protective coating with a self-healing ability and controlled properties are proposed. Finally the results of some properties of new silicide-type heterophase powders containing silicide and boride phases for a thermal spraying process and some properties of protective coating deposited on the niobium base alloys by means of a thermal spraying technique are presented.

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