High power diode laser modification of the wettability characteristics of an Al2O3/SiO2 based oxide compound for improved enamelling

Lawrence, Jonathan and Li, Lin and Spencer, Julian (1999) High power diode laser modification of the wettability characteristics of an Al2O3/SiO2 based oxide compound for improved enamelling. Materials Science & Engineering A. Structural Materials: Properties, Microstructure and Processing, 266 (1-2). pp. 167-174. ISSN 0921-5093

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Full text URL: http://dx.doi.org/10.1016/S0921-5093(99)00021-0

Abstract

High power diode laser (HPDL) surface melting of a thin layer of an amalgamated Al2O3/SiO2 oxide
compound (AOC) resulted in significant changes in the wettability characteristics of the material.
This behaviour was identified as being primarily due to: (i) the polar component of the AOC surface
energy increasing after laser melting from 2.0 to 16.2 mJm-2, (ii) the surface roughness of the AOC
decreasing from an Ra value of 25.9 to 6.3 μm after laser melting and (iii) the relative surface oxygen
content of the AOC increasing by 36% after laser melting. HPDL melting was consequently
identified as affecting a decrease in the enamel contact angle from 1180 prior to laser melting to 330
after laser melting; thus allowing the vitreous enamel to wet the AOC surface. The effective melt
depth for such modifications was measured as being from 50 to 125 μm. The morphological,
microstructural and wetting characteristics of the AOC were determined using optical microscopy,
scanning electron microscopy, energy disperse X-ray analysis, X-ray diffraction techniques and
wetting experiments by the sessile drop technique. The work has shown that laser radiation can be
used to alter the wetting characteristics of the AOC only when surface melting occurs.

Item Type:Article
Additional Information:High power diode laser (HPDL) surface melting of a thin layer of an amalgamated Al2O3/SiO2 oxide compound (AOC) resulted in significant changes in the wettability characteristics of the material. This behaviour was identified as being primarily due to: (i) the polar component of the AOC surface energy increasing after laser melting from 2.0 to 16.2 mJm-2, (ii) the surface roughness of the AOC decreasing from an Ra value of 25.9 to 6.3 μm after laser melting and (iii) the relative surface oxygen content of the AOC increasing by 36% after laser melting. HPDL melting was consequently identified as affecting a decrease in the enamel contact angle from 1180 prior to laser melting to 330 after laser melting; thus allowing the vitreous enamel to wet the AOC surface. The effective melt depth for such modifications was measured as being from 50 to 125 μm. The morphological, microstructural and wetting characteristics of the AOC were determined using optical microscopy, scanning electron microscopy, energy disperse X-ray analysis, X-ray diffraction techniques and wetting experiments by the sessile drop technique. The work has shown that laser radiation can be used to alter the wetting characteristics of the AOC only when surface melting occurs.
Keywords:high power diode laser (HPDL), vitrification, melting, enamel, adhesion, surface energy
Subjects:H Engineering > H680 Optoelectronic Engineering
H Engineering > H700 Production and Manufacturing Engineering
Divisions:College of Science > School of Engineering
ID Code:3173
Deposited By: Rosaline Smith
Deposited On:04 Aug 2010 22:38
Last Modified:13 Mar 2013 08:44

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