Thermomechanical behavior of resin bonded foundry sand cores during casting
Résumé
Foundry sand cores and bonding resin behaviors were investigated between room temperature and 450 °C. A series of experiments including DMA, DSC, TGA, dilatometry, tensile tests and creep tests were conducted on the resin. Sand core samples were tested under four-point bending loading with various thermomechanical histories and the tension-compression asymmetry was investigated by turning upside down the specimen. The deformation mechanisms as well as the effect of temperature, heating rate and applied load were studied. The microstructure variation-resin thermal aging relationship was discussed and established. It was found that the evolution of resin properties due to both thermal degradation and crosslinking depending on temperature history has a direct impact on core deformation.