Thermal stresses and their implication on cracking during laser melting of ceramic materials

A three-dimensional mechanical finite element model has been developed to investigate thermal stresses and their implication on cracking during laser melting of ceramic materials. Special effort has been devoted to the effects of latent heat of fusion and fluid flow of the melt pool on the thermal stresses. Results have indicated that, although the trends in the predicted maximum tensile stresses with respect to laser processing conditions are the same, the contours in the tensile stresses on the surfaces of the treated tracks are significantly different for two simulation cases, using thermal loads provided by different thermal models that either consider or neglect latent heat of fusion and fluid flow of the melt pool. Such simulated results for thermal stresses can be reasonably correlated with the degree of occurrence of cracks and the morphologies of the cracks experimentally formed, under the corresponding laser processing conditions. © 2004 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.