Prediction of cooling curves during solidification of Al 6061-SiC<inf>p</inf> based metal matrix composites using finite element analysis

In recent years, aluminium based cast composites have gained popularity in all the emerging fields of technology owing to their superior high stiffness and strength. The properties of cast composites are dictated largely by the solidification phenomenon, which needs to be well understood by foundry technologists. Information on the solidification studies of cast composites is scarce. However, the theoretical prediction of the solidification behaviour of cast composites by the use of commercially available finite element analysis (FEA) software has not yet been reported. The theoretical prediction can definitely yield good lot of information as regards the cooling rates of the cast composites saving enormous time in experimentation. In light of the above, the present investigation is aimed at the prediction of cooling curves of Al 6061-SiCp composites using finite element analysis. L-shaped composite castings were prepared using stir cast technique. The temperature of the composite during solidification was measured by K-type thermocouple, from which the cooling curves were constructed. Experiments were carried out over a range of particle weight percentage of 2-6 wt% in steps of 2 wt%. Comparison of the cooling curves of Al 6061-SiCp composite with the un-reinforced alloy reveals significant decrease in cooling rate with the addition of SiC particles. A two-dimensional transient heat transfer model was used in commercial finite element analysis software to predict the cooling curves of composite castings. The predicted cooling curves are compared with results obtained from experiments and found to be in good agreement. © 2009 Elsevier B.V. All rights reserved.