Modeling the Capillary Pressure for the Migration of the Liquid Phase in Granular Solid-Liquid-Vapor Systems: Application to the Control of the Composition Profile in W-Cu FGM Materials

Missiaen J.M. (1) , J.J. Raharijaona (1) , F. Delannay (2)

1 SIMaP - Science et Ingénierie des Matériaux et Procédés
2 UCL - Université Catholique de Louvain = Catholic University of Louvain

A model is developed to compute the capillary pressure for the migration of the liquid phase out or into a uniform solid-liquid-vapor system. The capillary pressure is defined as the reduction of the overall interface energy per volume increment of the transferred fluid phase. The model takes into account the particle size of the solid particle aggregate, the packing configuration (coordination number, porosity), the volume fractions of the different phases, and the values of the interface energies in the system. The model is used for analyzing the stability of the composition profile during processing of W-Cu functionally graded materials combining a composition gradient with a particle size gradient. The migration pressure is computed with the model in two stages: (1) just after the melting of copper, i.e., when sintering and shape accommodation of the W particle aggregate can still be neglected and (2) at high temperature, when the system is close to full density with equilibrium particle shape. The model predicts well the different stages of liquid-phase migration observed experimentally.

Mots clés: Capillary Pressure; Interface Energy; Liquid Bridge; Solid Skeleton; Vapor System

Domaines: Matériaux

Missiaen J.M., J.J. Raharijaona, F. Delannay. Modeling the Capillary Pressure for the Migration of the Liquid Phase in Granular Solid-Liquid-Vapor Systems: Application to the Control of the Composition Profile in W-Cu FGM Materials. Metallurgical and Materials Transactions A, 2016, 47 (11), pp.5569-5579. ⟨10.1007/s11661-016-3702-5⟩. ⟨hal-01463944⟩