The Present State of Modeling Entrainment Defects in the Shape Casting Process

The entrainment of oxide films into the bulk material has been shown to have a detrimental effect on casting integrity. A number of mechanisms have been shown to initiate the entrainment of oxide films, including: returning waves, plunging jets, bubble trails and fountains. Therefore, the assessment of the casting system for these features by the foundry engineer is critical in improving casting quality. The use of computational fluid dynamics software packages, which are now widely available to the foundry engineer, has allowed the foundry engineer to improve casting system design by using qualitative parameters. Optimization software is now an economically viable option for many foundries. However, optimization for casting integrity requires a quantitative casting integrity assessment technique, which allows the modeling and quantification of defects. Therefore, modeling and quantification of defects is becoming an ever more important research area to allow the optimization software manufacturers to meet the needs of industry. The current methods found in published literature for the modeling of casting defects have been described and critically reviewed, shedding light on the qualities and issues currently associated with the present available methods. However it is clear that further investigations and developments are still required to allow the accurate and efficient modeling of casting defects. The topics of research relating to the modelling of casting defects which require further investigation have been highlighted.