ISSN:
1013-9826
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
High-intensity pulsed ion beam (HIPIB) irradiation at 300 A/cm2 with a shot number of 1,and 5 was performed on the coatings and caused the modification of properties. Porosity and roughsurface of EB-PVD (Electron Beam-Physical Vapor Deposition) deposited ZrO2-7%Y2O3 coatingswith the thickness of 150 μm on heat-resistant steel have been characterized using the ultrasonicreflection coefficient phase spectrum. With increasing the shot number, the surface remelting andablating filled gaps and caves between columns, and induced more uniform and compact structure.The ultrasonic measurement was investigated using immersion focusing pulse echo method with a 10MHz transducer. The ultrasonic reflection coefficient related to frequency, velocity and attenuationcoefficient were analyzed based on the acoustic transmission model in a multi-layered structure. Forthe as-deposited coating and coatings irradiated by HIPIB with the shot number of 1 and 5, theultrasonic velocity changed from 2950 to 3170, and 3255 m/s respectively. The relationship betweenthe attenuation coefficient and the frequency has been deduced based on the numerical fitting of thephase spectrum. The corresponded expressions are 1.35 α = 0.105 f , 1.2 α = 0.045 f and 1.14 α = 0.035 f ,which displays that the attenuation coefficient decreases with the increasing of shot number. Theultrasonic results are in agreement with SEM observations, which have indicated that the coatingsbecame denser and uniform with increasing the shot number. From the velocity and attenuationcoefficient, the density, porosity, and microcracks of the coatings can be nondestructively evaluatedutilizing the method of this paper
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/57/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.373-374.358.pdf
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