Influence of the Structure of Protective Films on the Mechanical Breakdown of Passivity

1991 ◽  
Vol 20-28 ◽  
pp. 3823-3828
Minerals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 33
Author(s):  
Valérie Laperche ◽  
Bruno Lemière

Portable X-ray fluorescence spectroscopy is now widely used in almost any field of geoscience. Handheld XRF analysers are easy to use, and results are available in almost real time anywhere. However, the results do not always match laboratory analyses, and this may deter users. Rather than analytical issues, the bias often results from sample preparation differences. Instrument setup and analysis conditions need to be fully understood to avoid reporting erroneous results. The technique’s limitations must be kept in mind. We describe a number of issues and potential pitfalls observed from our experience and described in the literature. This includes the analytical mode and parameters; protective films; sample geometry and density, especially for light elements; analytical interferences between elements; physical effects of the matrix and sample condition, and more. Nevertheless, portable X-ray fluorescence spectroscopy (pXRF) results gathered with sufficient care by experienced users are both precise and reliable, if not fully accurate, and they can constitute robust data sets. Rather than being a substitute for laboratory analyses, pXRF measurements are a valuable complement to those. pXRF improves the quality and relevance of laboratory data sets.


Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 729
Author(s):  
Chanida Puttichaem ◽  
Guilherme P. Souza ◽  
Kurt C. Ruthe ◽  
Kittipong Chainok

A novel, high throughput method to characterize the chemistry of ultra-thin diamond-like carbon films is discussed. The method uses surface sensitive SEM/EDX to provide substrate-specific, semi-quantitative silicon nitride/DLC stack composition of protective films extensively used in the hard disk drives industry and at Angstrom-level. SEM/EDX output is correlated to TEM to provide direct, gauge-capable film thickness information using multiple regression models that make predictions based on film constituents. The best model uses the N/Si ratio in the films, instead of separate Si and N contributions. Topography of substrate/film after undergoing wear is correlatively and compositionally described based on chemical changes detected via the SEM/EDX method without the need for tedious cross-sectional workflows. Wear track regions of the substrate have a film depleted of carbon, as well as Si and N in the most severe cases, also revealing iron oxide formation. Analysis of film composition variations around industry-level thicknesses reveals a complex interplay between oxygen, silicon and nitrogen, which has been reflected mathematically in the regression models, as well as used to provide valuable insights into the as-deposited physics of the film.


2017 ◽  
Vol 506 ◽  
pp. 346-354 ◽  
Author(s):  
Rafael Maniglia ◽  
Kenneth J. Reed ◽  
John Texter
Keyword(s):  

1956 ◽  
Vol 27 (8) ◽  
pp. 862-866 ◽  
Author(s):  
Bernard D. Coleman

1986 ◽  
Vol 26 (3) ◽  
pp. 213-221 ◽  
Author(s):  
Francesco Di Quarto ◽  
Salvatore Piazza ◽  
Carmelo Sunseri

Author(s):  
A. M. Semiletov ◽  
◽  
A. A. Kudelina ◽  
Yu. I. Kuznetsov ◽  
◽  
...  

The production possibility of protective films of higher carboxylic (lauric, stearic (SA), oleic and linolenic) acids on a laser-textured surface of an aluminum alloy D16 is discussed. It is shown that such a modification leads to superhydrophobization (SHP) of the alloy surface. The most optimal type of laser processing has been determined: laser power is 12 W and the pass speed is 1000 mm / s. Profilometric measurements determined the average size of surface irregularities which is 6,47 microns. The degradation results of the SHP state in an aqueous solution of 0,05 M NaCl indicate greater stability of films formed from SA solutions. The protective ability of the coatings was evaluated by polarization measurements and corrosion tests in a salt chamber. It was found that films formed from an SA solution had the best anticorrosive properties. According to polarization measurements, an increase in ΔEpt = 220 mV, and the time of the first corrosion damage appears τcor = 384 h.


2015 ◽  
Author(s):  
Chilukuri Maheshwar

In February 2013, in the 2005 built 15500 TEU 397m long container ship EMMA MÆRSK a severe leakage occurred in as it was passing southbound through the Suez Canal. The leakage occurred due to mechanical breakdown of a stern thruster causing flooding of the shaft tunnel and filling up the engine room with 14000 m³ of seawater within a span of two hours, submerging the main engine cylinder heads-level equal to the outside water draft of 15.1 m. The cost of repairs and loss of revenue for six months amounted to a few million dollars. This paper highlights some of the lessons learned from this incident.


2007 ◽  
Vol 9 (2) ◽  
pp. 5-9 ◽  
Author(s):  
Roland Milker ◽  
Zbigniew Czech ◽  
Marta Wesołowska

Synthesis of photoreactive solvent-free acrylic pressure-sensitive adhesives in the recovered system The present paper discloses a novel photoreactive solvent-free acrylic pressure-sensitive adhesive (PSA) systems, especially suitable for the so much adhesive film applications as the double-sided, single-sided or carrier-free technical tapes, self-adhesive labels, protective films, marking and sign films and wide range of medical products. The novel photoreactive solvent-free pressure-sensitive adhesives contain no volatile organic compounds (residue monomers or organic solvent) and comply with the environment and legislation. The synthesis of this new type of acrylic PSA is conducted in common practice by solvent polymerisation. After the organic solvent are removed, there remains a non-volatile, solvent-free highly viscous material, which can be processed on a hot-melt coating machine at the temperatures of about 100 to 140°C.


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