Transient Elastic Thermal Stress Development During Laser Scribing of Ceramics
Author:
Modest Michael F.1, Mallison Thomas M.1
Affiliation:
1. Department of Mechanical Engineering, The Pennsylvania State University, University Park, PA 16802
Abstract
Lsaers are emerging as a valuable tool for shaping and cutting hard and brittle ceramics. Unfortunately, the large, concentrated heat flux rates that allow the laser to efficiently cut and shape the ceramic also result in large localized thermal stresses in a small heat-affected zone. These notable thermal stresses can lead to micro-cracks, a decrease in strength and fatigue life, and possibly catastrophic failure. In order to assess where, when, and what stresses occur during laser scribing, an elastic stress model has been incorporated into a three-dimensional scribing and cutting code. First, the code predicts the temporal temperature fields and the receding surface of the ceramic. Then, using the scribed geometry and temperature field, the elastic stress fields are calculated as they develop and decay during the laser scribing process. The analysis allows the prediction of stresses during continuous wave and pulsed laser operation, a variety of cutting speeds and directions, and various shapes and types of ceramic material. The results of the analysis show substantial tensile stresses develop over a thick layer below and parallel to the surface, which may be the cause of experimentally observed subsurface cracks.
Publisher
ASME International
Subject
Mechanical Engineering,Mechanics of Materials,Condensed Matter Physics,General Materials Science
Reference15 articles.
1. Copley, S. W., Wallace, R. J., and Bass, M., 1983, “Laser Shaping of Materials,” in Lasers in Materials Processing, E. A. Metzbower, ed., American Society for Metals, Metals Park, OH. 2. Yamamoto, J., and Yamamoto, Y., 1987, “Laser Machining of Silicon Nitride,” in International Conference on Laser Advanced Materials Processing—Science and Applications, Osaka, Japan, High Temperature Society of Japan, Japan Laser Processing Society, pp. 297–302. 3. DeBastiani, D., Modest, M. F., and Stubican, V. S., 1990, “Mechanisms of Reactions During CO2-Laser Processing of Silicon Carbide,” J. Am. Ceram. Soc., 73, No. 7, pp. 1947–1952. 4. Hasselman, D. P. H., Thomas, J. R., Kamat, M. P., and Satyamurthy, K., 1980, “Thermal Stress Analysis of Partially Absorbing Brittle Ceramics Subjected to Symmetric Radiation Heating,” J. Am. Ceram. Soc., 63, No. 1–2, pp. 21–25. 5. Thomas, J. R., Singh, J. P., and Hasselman, D. P. H., 1981, “Analysis of Thermal Stress Resistance of Partially Absorbing Ceramic Plate Subjected to Asymmetric Radiation: I—Convective Cooling at Rear Surface,” J. Am. Ceram. Soc., 64, No. 3, pp. 163–173.
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