ZrO2-Al2O3 eutectic plates produced by laser zone melting

• Published in: Journal of the European Ceramic Society Vol. 22; no. 2; pp. 191 - 198
• Main Authors: LARREA, A, DE LA FUENTE, G. F, MERINO, R. I, ORERA, V. M
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier 01.02.2002
• Subjects: Applied sciences; Building materials. Ceramics. Glasses; Ceramic industries; Chemical industry and chemicals; Exact sciences and technology; Miscellaneous; Technical ceramics; Mechanical properties; Twinning; Experimental study; Oxide ceramics; Plate; Zirconia; Phase transformation; Zone melting; Laser beam; Eutectic; Manufacturing; Microstructure; Alumina; Residual stress
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/S0955-2219(01)00279-5

Large surfaces of eutectic composites were directionally solidified from the melt, with very fine and uniform microstructures. Large surface plates of the Al2O3-ZrO2 eutectic, with thickness up to 250 micron, were grown by solidification using a modified laser zone melting method suitable for the preparation of large area samples. The surface of a ceramic precursor was scanned with a rectangular CO2 laser beam of 20 x 0.5 mm2 size which induced surface melting. The resulting microstructure was colony free and consisted of fine and alternating interpenetrating Al2O3 and ZrO2 single crystal lamellae. This microstructure was the basis for improvement of mechanical behaviour in the processed material. The interspacing, crystal structure and orientation relationship between the phases were determined. Solidification fronts were studied as a function of the processing conditions. A mapping of the residual stresses was performed along the transverse plate sections using micro-luminescence techniques. 23 refs.