Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Fracture and yield behaviour of wear and erosion resistant boron phosphide coatings for aerospace and automotive applications

Ogwu A. A., Hellwig T., Haddow D.

Archives of Materials Science and Engineering

2015

Vol. 75, nr 1

30--34

Purpose: The investigation of mechanical properties of boron phosphide thin film coatings prepared by PECVD. Design/methodology/approach: The hardness of the films was determined by nanoindentation. The fracture toughness was measured by Vickers indentation and the yield strength of the films on ZnS and <100> silicon substrate was measured by a simplified form of the spherical cavity model. Findings: The measured mechanical properties indicate that boron phosphide coatings have potential engineering applications beyond protecting infrared substrates from sand erosion in aerospace environments. Research limitations/implications: Their mechanical properties are comparable to those of DLC and Si-DLC films, in addition to their superior corrosion and sand abrasion resistance. Practical implications: Originality/value: Experimental data on the mechanical properties of boron phosphide coatings that indicate their surface protection promise in engineering applications.

Electrical resistivity of copper oxide thin films prepared by reactive magnetron sputtering

Ogwu A. A., Darma T. H., Bouquerel E.

Journal of Achievements in Materials and Manufacturing Engineering

2007

Vol. 24, nr 1

172-177

Purpose: Investigation the effect of varying r.f. power and oxygen flow rates during deposition on the electrical properties of copper oxide thin films prepared by reactive magnetron sputtering. Design/methodology/approach: The films were characterised by AFM, XPS, four point electrical resistivity probe measurements and spectrophotometry. Findings: The electrical sheet resistance of the films was found to vary from greater than 4 x 105 ohms/square for films prepared at 200W r.f. power to as low as 20 ohms/square for films prepared at 800W r.f. power. The variation in the electrical resistivity of the films with deposition conditions has been explained in terms of stoichiometric changes induced by copper or oxygen ion vacancies and neutral defects. Practical implications: The formation of these defects depends on the sticking coefficient, nucleation rates and the migration of impinging copper and oxygen species on the substrate during deposition. Originality/value: This information is expected to underlie the successful development of copper oxide films for solar windows and other semi-conductor applications including gas sensors.