Author | Slimane Adjerid, Joseph E. Flaherty, W. Hillig, J. Hudson and Mark S. Shephard |
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Title | Modeling and the Adaptive Solution of Reactive Vapor Infiltration Problems |
Year | 1995 |
Journal | Modelling and Simulation in Materials Science and Engineering |
Volume | 3 |
Pages | 737-752 |
Abstract | We develop a mathematical model of a reactive vapor infiltration (RVI) process for manufacturing the matrices of fiber-reinforced ceramic composites. The model considers the diffusion of silicon at elevated temperature into a compressed-powder pellet of either molybdenum or a mixture of molybdenum and molybdenum disilicide and its reaction to form the desired molybdenum disilicide matrix. Volume expansion and material distortion that may accompany the siliciding reactions are modeled by considering the medium to be a viscous fluid and coupling this mechanical model with the reaction-diffusion system. The partial differential system comprising the model is solved by adaptive finite element software having capabilities for automatic quadtree structured mesh generation, mesh refinement/coarsening, method order variation, and mesh motion. Temporal integration is controlled within a method-of-lines framework by backward difference software. Meshes can be moved to track material distortion or to reduce discretization errors. Computational solutions of one- and two-dimensional problems indicate that the adaptive software is a robust and effective tool for addressing composite-processing problems. |