Casting defects revealed can be repaired. Especially small defects such as microporosity are difficult to interpret using radiographic examination. If such defects are not detected by conventional non-destructive testing methods, in many instances these problems are only found after final machining, which results in scrapped castings. The added value invested in this scrap can significantly exceed the manufacturing costs of the unmachined casting, which is a small proportion of the finished assembly. For the foundryman, this is a challenge. To secure an early recognition of such defects, innovative technologies must ensure a robust product quality. Comprehensive studies to detect microporosity by virtual tools let Tycon Alloy Industries decide to apply the latest simulation software from MAGMA to help significantly reduce such costs.
For one of Tycon's products, the customer required zero defects in a critical area. Radiography revealed no defect in the as-cast component, however microporosity was found in the bore after final machining. Using MAGMA5 to verify this issue confirmed that there was microporosity present in the critical area. The results allowed technicians to modify the runner and riser confi guration to eliminate the defect. The casting trials indicated that the revisions made resulted in no porosity in the critical area, leading to a sound casting.