• Journal of Korea Foundry Society
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• v.44 no.3
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• pp.70-76
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• 2024

Sodium silicate binder is eco-friendly inorganic binder to substitute organic binder in foundry industry, but it has low stability at moisture. In this study, the bending strength of sand cores with sodium silicate binder at various curing condition was measured for confirm the effect of moisture content in cured sodium silicate binder on the strength and stability. The sodium silicate binder generates stable binder bridge with silicate structure of Q³ and Q² at 130℃. The maximum bending strength of sand cores was not affected by curing conditions, because the silicate structure of binder bridges was similar. However, the lower moisture content of cured sodium silicate binder, stability of strength was enhanced. Therefore, it was confirmed that the moisture content of cured sodium silicate binder is important factor at stability of sodium silicate binder.