Modelling of transverse segregation on centrifugally-cast functionally graded composites

Alexandre Velhinho, Gonçalo Rodrigues, José Paulo Mota, Rodrigo Martins

Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia; CENIMAT/I3N - Materials Research Centre


Two technological variants of centrifugal casting (CC) are available to fabricate functionally graded particle-reinforced metal composites. While models abound for the commonest variant (radial CC), its alternative (longitudinal CC) has mainly been neglected in that regard. Longitudinal CC is distinguished by the existence of an acceleration ramp, during which the centrifugal acceleration varies with time. Some operating conditions have been shown to be able to generate different disturbances to the intended spatial distribution of reinforcements within the composite. The present work reports a modelling effort undertaken to quantify the effects of the acceleration ramp, as well as predicting the occurrence of transverse segregation. The resulting mathematical framework, which required a modification of the Stokes’ equation in order to contemplate de specific effects of the solidification front on particle distribution, has been implemented in the gPROMS software environment.