The Oxidation Stability of Boron Nitride Thin Films on MgO and TiO2 Substrates

1991 ◽  
Vol 250 ◽  
Author(s):  
Xiaomei Qiu ◽  
Abhaya K. Datye ◽  
Robert T. Paine ◽  
Lawrence. F. Allard

AbstractThe stability of BN thin film coatings (2–5 nm thick) on MgO and TiO2 substrates was investigated using transmission electron microscopy (TEM). The samples were heated in air for at least 16 hours at temperatures ranging from 773 K - 1273 K. On MgO supports, the BN thin film coating was lost by 1073 K due to a solid state reaction with the substrate leading to formation of Mg2B2O5. No such reaction occurred with the TiO2 substrate and the BN was stable even at 1273 K. However, the coating appeared to ball up and phase segregate into islands of near-graphitic BN and clumps of TiO2 (rutile). The oxidizing treatment appears to promote the transformation from turbostratic BN to graphitic BN.

2013 ◽  
Vol 594-595 ◽  
pp. 730-734
Author(s):  
Мazhyn Skakov ◽  
Bauyrzhan Rakhadilov ◽  
Gaukhar Karipbayeva

A Possibility of R6M5 High-Speed Steel Strengthening by Finishing Plasma Strengthening(FPS) Method to Application of Sic Thin Film Coatings were under Research. by Scanning Electronmicroscopy and X-Ray Analysis Conducted a Comparative Study of the Structure, Phase and Chemicalcomposition before and after Application of Sic Thin Film Coating of R6M5 High-Speed Steel Surfacelayer. it is Experimentally Stated, that the Coverage of Sic Applied Method FPS Consists of Fineglobular Shape at the Size of 100-300 Nm. Determined that the Microhardness of R6M5 Steel Surfaceafter Application Sic Coating Increased Almost to 2.5 Times Comparing to Original. it is Shown Thatthe Application of Sic Thin Film Coating by FPS Method is a Promising Highly Effective Method Ofcutting Tools Surface Strengthening Made from High Speed Steels.


2008 ◽  
Vol 373-374 ◽  
pp. 722-725 ◽  
Author(s):  
Ke Dong Song ◽  
Peng Fei Wen ◽  
Tian Qing Liu

Initial attachment and spreading of the inoculated cells determines the long-time viability of cells onto biomedical scaffolds designed for various orthopedic or other clinical applications. The aim of this study was to investigate the influence of biomimetic thin film coating surfaces of bio-derived bone scaffolds with collagen proteins and chitosan on bone marrow mesenchymal stem cells interactions in order to improve cell adhesion, spreading and proliferation. These two merits were used synthetically to generate apatite-based materials that can function as allograft bone grafts in humans. In this study, the thin film coatings were operated by means of soaked, pre-frozen, and freeze-dried step by step. All coatings were characterized using Raman spectra, inverted microscope, atomic force microscopy, and scanning electron microscopy. After that, the bio-derived bone scaffolds with or without thin film coatings were used in bone marrow mesenchymal stem cell culture experiments to study cell adhesion, spreading, viability, proliferation and morphology. Then, the biological morphologies of the fabricated cell-scaffold constructs were detected by scanning electron microscope (SEM). The cell reactions were investigated concerning cell adhesion, migration, spreading, and proliferation under inverted microscope and fluorescence microscopy. The results showed that the bio-derived bone scaffold treated with thin film coatings by using rat-tail type I collagen and chitosan improved the adhesion and spreading of mesenchymal stem cells in comparison to the untreated one. Besides, cell viability and morphology were not affected by the presence of either type of thin film coating. Still, the results assay revealed an increased proliferation of bone marrow mesenchymal stem cells on both types of thin film coatings compared to coating with non-coated controls.


2021 ◽  
Vol 2059 (1) ◽  
pp. 012017
Author(s):  
Y V Panfilov ◽  
L L Kolesnik ◽  
A V Gurov

Abstract Thin film materials particles creation pulsed methods such as magnetron sputtering HiPIMS, pulsed laser deposition PLD, vacuum arc pulsed discharge, high-intensity pulsed ion beam impact HIPIB, as well, were described. It was shown that the stream of material, created by means of an explosion action such as ablation, avalanche paired impacts and microsecond electrical disruption as well creates preconditions for nanocrystalline thin film coating manufacture.


2021 ◽  
Vol 341 ◽  
pp. 00016
Author(s):  
Andrei Gorin ◽  
Alexandr Novikov ◽  
Svetlana Karpeeva ◽  
Мaria Tokmakovа

The article provides information on the creation of modified friction surfaces. The results of the analysis of the applied antifriction film coatings are presented. One of the main problems in the application of thin film coatings is the lack of technological modes recommended by the manufacturer. The composition of the film anti-friction coating is described. The results of experimental studies of the deposition of thin film coatings are presented. Selected pneumatic spray gun for depositing of thin film coating. A series of experiments were carried out to identify the technological modes of applying thin film coatings. A qualitative and quantitative analysis of the results of applying thin film coatings has been carried out. A functional diagram of the application of an antifriction film coating is proposed. On the basis of the conclusions made, recommendations are given on the technological modes of applying thin film antifriction coatings on the modified friction surface.


Author(s):  
T. P. Nolan

Thin film magnetic media are being used as low cost, high density forms of information storage. The development of this technology requires the study, at the sub-micron level, of morphological, crystallographic, and magnetic properties, throughout the depth of the deposited films. As the microstructure becomes increasingly fine, widi grain sizes approaching 100Å, the unique characterization capabilities of transmission electron microscopy (TEM) have become indispensable to the analysis of such thin film magnetic media.Films were deposited at 225°C, on two NiP plated Al substrates, one polished, and one circumferentially textured with a mean roughness of 55Å. Three layers, a 750Å chromium underlayer, a 600Å layer of magnetic alloy of composition Co84Cr14Ta2, and a 300Å amorphous carbon overcoat were then sputter deposited using a dc magnetron system at a power of 1kW, in a chamber evacuated below 10-6 torr and filled to 12μm Ar pressure. The textured medium is presently used in industry owing to its high coercivity, Hc, and relatively low noise. One important feature is that the coercivity in the circumferential read/write direction is significandy higher than that in the radial direction.


1996 ◽  
Vol 452 ◽  
Author(s):  
U. Klement ◽  
D. Horst ◽  
F. Ernst

AbstractThe objective of this work is to find a material to replace amorphous hydrogenated silicon used as photosensitive part in the “retina” of an “electronic eye”. For that reason, ZnS, ZnSe, CdS and CdSe were chosen for investigations. Thin films, prepared by chemical vapour deposition, were characterized by transmission electron microscopy. The observed microstructures were correlated with the optoelectronic properties of these materials. CdSe was found to be the most promising material for our application. Hence, the influence of a dielectric interlayer and the effects of additional annealing treatments were analyzed for CdSe and will be discussed with respect to the optimization of the material.


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