MAGMASOFT® showed regions where directional solidification could be improved, right where the castings were leaking (shown above – colors indicate time of solidification). At the same location, microporosity stretched through the wall of the part. To eliminate the leak, microporosity cannot be allowed to reach through the wall of the casting. In MAGMASOFT®, the Niyama Criterion is commonly used to identify regions that may contain microporosity.
Engineers at MAGMA ran a design of experiments (DOE) that tested different gate length and gate positions. The DOE yielded a combination of gate dimensions that eliminate the leak path, while avoiding forming a new leak along the inner diameter a of the casting. Below, we can see low Niyama values in red, which show a risk of leaking.