Coupling Solidification Simulation On Particle Reinforced Functional Material And Experimental Research

Recent numerical researches on the flow field of particle reinforced aluminiummatrix graded material during centrifugal casting are conducted on the premise ofconstant matrix viscosity. But actually matrix viscosity should be considered as afunction of temperature. Based on the general multiphase model of Gao(2007), wedeveloped an experimental viscosity-temperature function and a numerical investigationof the solidification process by centrifugal casting of SiC reinforced aluminium matrixgraded materials is conducted using field coupling method, which starts by measuringthe instantaneous temperature field at the beginning of each time step, then viscosityfield is computed using viscosity-temperature function, with which the instantaneousflow field is obtained.A predictive model with viscosity-temperature coupling method based on thegeneral multiphase model has been developed for FGM solidification by centrifugalcasting. Separately using ZL104alloy and ZL109alloy as the matrix and SiC as theparticle phase, experiments were performed to validate the model. This coupling modelprediction of particle volume fraction distribution during solidification is validatedagainst the experimental results and shows its better agreement with the practice.Based on the viscosity-temperature coupling method, a predictive model usingAl-Mg-Si alloy as the matrix and Si/Mg2Si as the particle phase has been developed byintroducing UDF functions to simulate the separating out process. The contrast analyseof microstructure shows that better pouring temperature is720-750℃. A segregatedsudden changed model of Si/Mg2Si particles has been developed through the contrastbetween experimental and simulating value, which apparently approving the simulationmodel. Some flaws of the model have been pointed out and to which the correspondingexplains have been put forward.