Experimental and Numerical Investigation of Water Quench Cooling of Aluminum Cylinder Heads

Quenching is a common heat treatment technique to improve mechanical properties of metal components. In particular the water quench process is a widely adopted procedure in automotive and aerospace industries due to the high level of achievable material performance, process robustness and cost efficiency. The objective of the current study was to predict the cooling of a cylinder head and an engine block during quenching. Applied 3D CFD code AVL FIRE^® offers state-of-the art modeling functionality in the field of quenching. Implemented models cover physical specifics of the thermal treatment process, which significantly influence the properties of cast materials. In the submersion (or direct) quenching phase of the heat treatment process, solutionized components are submerged in water. Initially film boiling regime is present slowing down the heat removal, followed by transition into nucleate boiling and finishing in single phase cooling after the solid has cooled down beneath the saturation temperature of the quench medium.   Residual stresses resulting from the heat treatment process are affected by part orientation, initial part temperature and water temperature, therefore accurate prediction of local temperature histories within the structure is crucial for reliable stress prediction. Different components have been investigated experimentally and numerically. Phase distributions and local flow phenomena have been captured in measurements performed by Ford Motor Company, numerically predicted temperatures, phase distributions and flow details have been compared with the experimental evidence.