Abstract
<title>Abstract</title> <p>The viscoelastic behavior of granular materials containing liquid phases plays a crucial role in high-temperature metallurgical processes. However, such systems often exhibit poor wettability and high surface tension (e.g. 0.4 ~ 1.8 N/m), where liquid bridges are unlikely to form, in contrast to conventional wet granular systems with good wettability and small surface tension (e.g. 0.02 ~ 0.07 N/m) studied at room temperature. In this study, we investigate the applicability of conventional scaling laws for the storage modulus G′ to high-temperature systems using mixtures of alumina beads with molten Sn, Cu, Fe, and oxide. Oscillatory shear measurements and X-ray CT observations were conducted to evaluate rheological behavior and microstructure. All systems exhibited solid-like behavior, but the dependence of G′ on surface tension deviated significantly from conventional scaling laws. X-ray CT analysis revealed that the liquid phase avoids solid–solid contacts and instead occupies larger voids, preventing liquid bridge formation. By evaluating different interfacial deformation mechanisms, we found that G′ scales with the effective spring constant associated with particle rotation at the gas–liquid interface. These results demonstrate that, under poor wettability conditions, viscoelasticity is governed not by capillary bridges but by interfacial rotational mechanics, providing a new framework for understanding and controlling high-temperature granular systems.</p>