Detection of Core Fracture in Inorganically Bound Cast-in Sand Cores by Acoustic Microphony

Abstract

This article suggests a new method to detect the fracture of cast-in sand cores. The goal of this approach is to reduce the time and efforts as well as increase the stability of the decoring process. A testing geometry and a test rig were built to explore the decoring process in the laboratory in order to test this approach. The proposed method is based on acoustic microphony to determine any fractures and loss of contact between a casting part and the cast-in sand cores that shall be removed by a mechanical decoring process. By the use of numerical tools a prediction of the occurring eigenmodes of theoretical decoring states is possible. This method is particularly suitable for cast-in geometries that can-not be monitored by visual inspections, such as cooling channels in the cylinder heads of combustion engines.