Predicting the occurrence and effects of defects in castings

Casting designs are generally based on strength of materials calculations and the experience of the designer. This process leads to incremental development of designs utilizing factors of safety, which lead to increased component weights and inefficient use of materials. In castings, unquantifiable factors (such as shrinkage, porosity, hot tears, and inclusions) lead to conservative design rules. Non-destructive testing does not give the designer a way to assess the effect of indications on part performance. This article describes recent work to predict the occurrence and nature of defects in castings and determine their effect on performance.