Foundry sand core property assessment by 3-point bending test evaluation

tImproved understanding of foundry sand core properties is a key requirement for high precision cast-ing process development. The present work demonstrates the potential to evaluate mechanical andfunctional sand core properties using precisely acquired 3-point bending test load curve data applyingstandard bending test geometries.Four organic binder systems have been investigated. Further to bending strength and the elastic mod-ulus, which can be directly derived from the load curves, a load curve pre-treatment to eliminate samplesettlement effects was applied for a corrected deflection and stiffness analysis. The consumed mechanicalwork shows characteristic elastic and plastic work portions until fracture, which are specific for differentsand cores, respectively their condition. Dimensionless indicators to quantify core brittleness have beendeveloped based on curve and on work parameters.In general for mechanical evaluations of resin bonded sand cores, visco-plastic effects need to be con-sidered, as for not fully hardened binder systems decreased strength, deflection and work of fracturewere observed at lower load speeds.The benchmark results show that the load curve evaluation concept is a suitable tool to analyse foundrysand core properties more sensitively.