Extension of SPH to predict feeding,freezing and defect creation in low pressure die casting

Low pressure die casting is used to manufacture complex metal components where there is a need for high structural integrity. In this process, liquid metal is fed from below into the die used to form the component under a positive pressure. Smoothed particle hydrodynamics (SPH) is a meshfree Lagrangian method that has specific advantages for modelling such material forming applications. This paper describes extensions to the SPH method for predicting shrinkage of the cooling metal, tracking of oxide formation, prediction of feeding, solidification front dynamics and finally direct prediction of the residual pressure distribution in the solidified metal and of cavity defect formation. These are demonstrated using a simple two dimensional example which contains the essential features of an engine block.