Thermal expansion coefficient of a NiCoCrAlY-ZrO2(Y2O3) coating by a digital image processing based dilatometer. (1st January 2000)

• Record Type: Journal Article
• Authors: Beghini, M.; Bertini, L.; Frendo, F.
• Is Part Of: International journal of material & product technology. Volume 15:Number 1/2(2000)
• Page Start: 78
• Page End: 90
• Publication Date: 2000-01-01
• Subjects: ceramic coatings -- thermal expansion coefficient -- image processing; Manufacturing processes -- Periodicals; Materials -- Testing -- Periodicals; 620.11
• Languages: English
• ISSNs: 0268-1900

Abstract

A procedure for thermal expansion coefficient measurement is presented. A quartz dilatometer and a digital image processing technique were employed to obtain an accurate measure of the elongation of a prismatic specimen placed in a tubular furnace. By testing several symmetrically coated specimens the thermal expansion coefficient of a NiCoCrAlY-ZrO2 (Y2 O3 ) coating was obtained. The relationships for deducing the coefficient of the coating were derived by the multi-layer beam model and their sensitivity to experimental errors was discussed. Results were obtained in the range 20°C-950°C, both for the substrate and coating materials. An estimate of results accuracy is given, based on a Monte Carlo simulation of uncertainties.