Modeling of transport phenomena in direct laser deposition of metal matrix composite

Direct laser deposition of metal matrix composite provides a very promising method to fabricate non-homogeneous material in one step directly from CAD drawings. During this process, reinforcing hard particle phase is mixed with the liquid matrix material to change the material property. Despite its usefulness, an understanding of interaction between the reinforcing particle and matrix material in the molten pool still remains as a challenge to determining the final properties of the fabricated composite. In this paper, distinct comprehensive modeling is presented to describe the complex transport phenomena during direct laser deposition of metal matrix composite. The molten pool thermal and fluidic behavior with the inter-phase coupling between particles and matrix material is modeled. To track the particle distribution, a species transport equation for particle mass fraction, as well as algebraic expressions considering possible different phase velocities, is combined with the other deposition governing equations. The mixture properties of composite are obtained by incorporating the volume fraction of each phase. The simulated average particle volume fractions agree with the experimental results and the model can be used to design the properties of the composite synthesised by the laser direct deposition process. (C) 2011 Elsevier Ltd. All rights reserved.