Analysis of casting defects of an eyepiece part

The problem and the task formulation

To effectively prevent casting defects, it is necessary to have opportunity for precise determination of their causes. Above all, it concerns internal defects of the casting that can be identified only after mechanical processing. The client requested us to help solve the following problem: rejection rate was up to 90% in the castings of the binocular right eyepiece lid.

Problem-solving technique

To perform the project, the client handed to us drawings for products and the casting rigs. We made the work in cooperation with the client�s specialists. First, we made a 3D model of the casting, punch and die. All procedures were performed under CAD/CAE/PDM.

Then we used a specialized program package PROCAST by ESI Group Company including simulation of the casting processes, which showed that soon after the beginning of the filling process the feeder channeling metal to the mould was frozen.

Then, when the casting was solidified, metal was hardened without a further filling by liquid phase, which caused the defects.

Analysis of casting defects showed that if we optimized the feeder cross section it would sharply reduce shrinkage porosity in the area of mechanical processing, thereby reducing the rejection rate at the output of the production line where the eyepiece was manufactured.

Results

During the research we identified the cause of the casting defects, which allowed us to formulate recommendations to avoid porosity in the areas of mechanical processing. Our work helped the client radically reduce rejection rates in the casting production.