Product Description
PaperID: 960
EventID: 5
Author: A. Kavanagh, MR. Jolly, S. Ramirez-Garcia, K. Williamson, DePuy Johnson & Johnson
Abstract: Computer numerical modelling of the metal pouring process has been used to investigate the mechanisms of entrained inclusions which contribute to high scrap rates and significant manual rework during the manufacture of investment cast orthopaedic medical devices. Manifesting themselves as inclusions and pinhole voids the defects are uncovered in the post-casting automated machining operations when the cast skin is mechanically removed. The general purpose CFD package, Flow-3D, with particle tracking capability has been applied to the mould filling process to model surface slag within the crucible and the subsequent transport of slag and refractories during mould filling. The entrainment of ash particles observed inside a sampling of uncast moulds post preheating was also simulated during mould filling. The modelled results have been successfully linked to an in-depth foundry study that examined the relationship between the casting location within the mould to the occurrence of the defect. Alloy melting and puring practices combined with incomplete mould burnout have been seen as the main contributing factors to the occurrence of the defect.
Paper Pages: 14
Paper Year: 2012
Paper Index: 17:01
Paper Source: 79
