Modeling of Distortion during Casting and Machining of Aluminum Engine Blocks with Cast-in Gray Iron Liners

Artikel i vetenskaplig tidskrift, 2012

A method for quantifying distortions arising in engine blocks of aluminium with liners of grey iron has been developed based on virtual finite element based simulation tools. The key processing steps comprise the convection cooling step, associated with shrinkage and residual stress build-up, and the machining step. The engine block has been modelled using the finite element method and machining has been simulated using the element-removal technique. The mechanical behaviour of aluminium has been characterised by tensile tests at different temperatures and strain rates. The results were used for calibration of material models capturing the viscoplastic behaviour at higher temperatures. Finally, following the key process steps, results from a complete process analysis are reported comprising the initial stress build-up based on the cooling associated with initial out-of-roundness and predictions of final residual stress state in the block and out-of-roundness of the liners after various machining operations.