Use of the thin coatings to control characteristics of radiating and scattering objects

1998 ◽  
Author(s):  
F.G. Bogdanov ◽  
D.D. Karkashadze ◽  
D.A. Metskhvarishvili
Keyword(s):  
Thin Coatings

scholarly journals Study on the Influence of the Ball Material on Abrasive Particles’ Dynamics in Ball-Cratering Thin Coatings Wear Tests

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 668
Author(s):  
Gustavo Pinto ◽  
Andresa Baptista ◽  
Francisco Silva ◽  
Jacobo Porteiro ◽  
José Míguez ◽  
...  
Keyword(s):  
Aisi 304 ◽  
Thin Coatings ◽  
Iron And Steel ◽  
Test Configuration ◽  
Abrasive Particles ◽  
Aisi 52100 ◽  
Aisi 304 Steel ◽  
Aisi 52100 Steel ◽  
Steel Balls ◽  
Particles Dynamics

Micro-abrasion remains a test configuration hugely used, mainly for thin coatings. Several studies have been carried out investigating the parameters around this configuration. Recently, a new study was launched studying the behavior of different ball materials in abrasive particles’ dynamics in the contact area. This study intends to extend that study, investigating new ball materials never used so far in this test configuration. Thus, commercial balls of American Iron and Steel Institute (AISI) 52100 steel, Stainless Steel (SS) (AISI) 304 steel and Polytetrafluoroethylene (PTFE) were used under different test conditions and abrasive particles, using always the same coating for reference. Craters generated on the coated samples’ surface and tracks on the balls’ surface were carefully observed by Scanning Electron Microscopy (SEM) and 3D microscopy in order to understand the abrasive particles’ dynamics. As a softer material, more abrasive particles were entrapped on the PTFE ball’s surface, generating grooving wear on the samples. SS AISI 304 balls, being softer than the abrasive particles (diamond), also allowed particle entrapment, originating from grooving wear. AISI 52100 steel balls presented particle dynamics that are already known. Thus, this study extends the knowledge already existing, allowing to better select the ball material to be used in ball-cratering tests.

scholarly journals Bio-based polyurethane nanocomposite thin coatings from two comparable POSS with eight same vertex groups for controlled release urea

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lixia Li ◽  
Meng Wang ◽  
Xiandong Wu ◽  
Wenping Yi ◽  
Qiang Xiao
Keyword(s):  
In Situ Polymerization ◽  
Polyhedral Oligomeric Silsesquioxanes ◽  
Poly Ethylene Glycol ◽  
Thin Coatings ◽  
Polyurethane Coatings ◽  
Coated Urea ◽  
Poly Ethylene ◽  
Coated Fertilizer ◽  
Polyurethane Matrix

AbstractNanocomposite modification has attracted much attention in improving properties of bio-based polymer coating material for coated fertilizer. Herein two comparable polyhedral oligomeric silsesquioxanes (POSS), with eight poly(ethylene glycol) (PEG) and octaphenyl groups attached to the cage, respectively, were successfully incorporated into thin castor oil-based polyurethane coatings via in-situ polymerization on the urea surface. The nanostructure coatings are environmentally friendly, easy to prepare, and property-tunable. The results show that the vertex group of POSS had a pronounced influence on dispersion level and interaction between polyurethane and POSS that well-tuned the release pattern and period of coated urea, even at the coating rate as low as of 2 wt%. The liquid POSS with long and flexible PEG groups had better compatibility and dispersibility in polyurethane matrix than the solid POSS with rigid octaphenyl groups, as evidenced by SEM/EDS. The unique properties were resulted from the different extents of physical crosslinkings. This modification of bio-based polyurethane coating with POSS provided an alternative method of regulating and controlling the properties of coated fertilizer.

Mechanical Properties of Pyrolytic "SiOCN" Thin Coatings

1993 ◽  
Vol 308 ◽  
Author(s):  
Sandrine Bec ◽  
André Tonck ◽  
Jean-Luc Loubet
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Ceramic Coatings ◽  
Optical Observation ◽  
Thin Coatings ◽  
Polymer Precursors ◽  
Polymeric State

ABSTRACTPyrolysis of polymer precursors (polysilazane) is a technologically and economically interesting way to produce thin ceramic coatings. However, many cracks appear and decohesion occurs during pyrolysis when the ceramic coatings (SiOCN) are thicker than 0.5 micrometers. In order to understand these cracking phenomena, the coatings are mechanically characterized by nanoindentation at different stages of the pyrolysis heat treatment.During pyrolysis, the cracking temperature is detected by in-situ optical observation. The thickness of the coatings varies during pyrolysis from 3 micrometers at the polymeric state to 1 micrometer at the ceramic state. The coatings' properties, hardness and Young's modulus are evaluated after heat treatment, taking into account the substrate's influence. A large variation of these properties occurs at the cracking temperature. Both the hardness and the Young's modulus are multiplied by a factor of 10. By analysing these results, we show that cracking is correlated with the evolution of the coatings' mechanical properties during the transformation.

X-Ray Analysis of Residual Stresses and Textures in Thin Coatings

1993 ◽  
Vol 133-136 ◽  
pp. 117-124 ◽  
Author(s):  
A. Schubert ◽  
B. Kämpfe ◽  
E. Auerswald
Keyword(s):  
Residual Stresses ◽  
Thin Coatings ◽  
X Ray

I'he Detectability Limits of Thin Coatings Measured with the Eleetron Mieroprobe

1973 ◽  
Vol 64 (9) ◽  
pp. 655-661
Author(s):  
Siegfried Baumgartl ◽  
Peter L. Ryder ◽  
Hans-Eugen Bühler
Keyword(s):  
Thin Coatings

Thin coatings with tetrahedral amorphous carbon structure and their behavior in boundary lubrication conditions

2020 ◽  
pp. 506-511
Author(s):  
V.D. Samusenko ◽  
I.A. Zavidovskii ◽  
O.A. Streletskii ◽  
I.A. Buyanovskii ◽  
M.M. Khrushchov ◽  
...  
Keyword(s):  
Amorphous Carbon ◽  
Boundary Lubrication ◽  
Carbon Structure ◽  
Thin Coatings ◽  
Tribological Tests ◽  
Tetrahedral Amorphous Carbon ◽  
Structural Peculiarities ◽  
Lubrication Conditions

The results of an investigation of the structural peculiarities of the thin ta-C coatings obtained by the method of impulse arc sputtering of graphite and of their tribological tests in boundary lubrication conditions are presented.

Protective Thin Coatings Technology

2021 ◽  
Author(s):  
Sam Zhang ◽  
Jyh-Ming Ting ◽  
Wan-Yu Wu
Keyword(s):  
Thin Coatings
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