Technical Paper Fewer Sand Inclusion Defects by CAE

The use of casting CAE (solidification analysis and fluidity analysis) technologies, developed through previous research activities, has enabled, to some extent, a reduction in both shrinkage cavities, through an improved feeding method, as well as misruns and cold shut defects, thanks to an improved runner. On the other hand, however, throughout the entire casting process, the work hours required by longer processing time, damage to tools, reworking and other factors caused by inclusions that result in processing defects represent significant problems. CAE technology was previously unable to resolve such problems due to the lack of a function to analyze fluidity and the difficulty in identifying the sources of inclusions. These problems are, in fact, dealt with by intuition and experience. To solve these problems encountered in casting, an analytical technique is being scrutinized to forecast the behaviors of inclusions in fluids. Parts of the undercarriage of large bulldozers have presented these problems due to machining defects caused by inclusions. This paper reports on the activities, including a reduction in the inclusion defects, machining margins and machining processes for the undercarriage parts by using a technique to forecast inclusions by CAE.