The weld pool region of welded cast metal-matrix ceramic-particulate composites

The successful application of ceramic-particulate reinforced metal matrix composites as engineering materials requires that they be amenable to fabrication by joining processes such as welding. In such a case, the weld pool would undergo intense agitation during welding and the ceramic particulates would tend to segregate, causing deterioration in the mechanical and wear properties of the joined portion. In the present work, a thermo-physical model has been used to predict the velocities of fluid movement in the weld pool as a function of heat input. An attempt has been made to combine analytical and numerical methods in order to ensure the accuracy of the model's predictions and at the same time to make the computation faster. Aluminium-alumina and aluminum-silicon carbide composites were prepared by casting and the resultant plates of standard dimensions and thicknesses were welded using the MIG process. The distribution of the ceramic particulates and their reaction with the matrix in the welded zone w...