WETTABILITY OF MOLTEN Fe-Si-B ALLOY ON GRAPHITE, Al2O3, AND h-BN SUBSTRATES

Abstract

Fe-26.38Si-9.35B alloy (numbers in mass %) is of interest as a phase change material (PCM) because it exhibits high thermal conductivity, moderate melting point, high latent heat, and low cost. This study offers valuable insights into the contact angles of molten eutectic Fe-26.38Si-9.35B alloy on various substrates using the sessile drop method. Moreover, the reactivity has been investigated by examining the cross-sections between Fe-26.38Si-9.35B droplets and substrates with a scanning electron microscope (SEM). The purpose of this study is to find a proper refractory material for the new Fe-26.38Si-9.35B PCM. These wetting tests confirm that the contact angle between molten Fe-26.38Si-9.35B and Al2O3 is about 112o. Molten Fe-26.38Si-9.35B spreads over the graphite plate and the contact angle is estimated to be 31o and a continuous silicon carbide (SiC) layer is formed between the molten Fe-26.38Si-9.35B and graphite. Interestingly, three melting/solidification cycles have been performed on hexagonal boron nitride (h-BN) substrate at the temperature range of 1100-1550 oC. The contact angle is observed to be 142o in the first cycle, 105o in the second cycle, and 130o in the third cycle. This study contributes to our understanding of the wettability properties of molten Fe-26.38Si-9.35B alloy on various substrates.