Glass-to-metal seal absorb the stresses from thermal expansion mismatches. Due to its very low vapor pressure, indium finds use in glass-metal seals used in vacuum technology. Gallium is a soft metal with melting point at 30 °C. It readily wets glasses and most metals and can be used for seals that can be assembled/disassembled by just slight heating. It can be used as a liquid seal up to high temperatures or even at lower temperatures when alloyed with other metals (e.g. as galinstan). Mercury is a metal liquid at normal temperature. It was used as the earliest glass-to-metal seal and is still
Liquid metal solution slowly, producing gallates like [Ga(OH)], which makes the surface of gallium negatively charged and cations accumulated nearby, and thus the electrically charged interface forms into a uniform diffuse electrical double layer (EDL) . The electrons flowing internally from Al to the liquid metal preferentially deoxidate the oxidized gallium near the Al, which alters the distribution of the charges across the EDL, leading to the generation of a potential gradient along the liquid metal surface. According to Lippmann's equation, the alteration of the EDL induces an imbalance of the surface tension on the liquid metal. Following the Young-Laplace equation, the