Liquid metal Liquid metal Liquid metal consists of alloys with very low melting points which form a eutectic that is liquid at room temperature. The standard metal used to be mercury, but gallium-based alloys, which are lower both in their vapor pressure at room temperature and toxicity, are being used as a replacement in various applications. A few elemental metals are liquid at or near room temperature. The most well known is mercury(Hg), which is molten above −38.8 °C (234.3 K, −37.9 °F). Others include caesium(Cs), which has a melting point of 28.5 °C (83.3 °F), rubidium (Rb)(39 °C [102 °F]), francium
Liquid metal embrittlement An incubation period and a slow pre-critical crack propagation stage generally precede final fracture. It is believed that there is specificity in the solid-liquid metals combinations experiencing LME. There should be limited mutual solubilities for the metal couple to cause embrittlement. Excess solubility makes sharp crack propagation difficult, but no solubility condition prevents wetting of the solid surfaces by liquid metal and prevents LME. Presence of an oxide layer on the solid metal surface also prevents good contact between the two metals and stops LME. The chemical compositions of the solid and liquid metals affect the severity of embrittlement. Addition