Furnaces for melting

Crucible furnaces

Melting is the direct transition of a substance from a solid to a liquid state. If this process takes place at constant pressure for pure substances, the melting temperature is clearly determined. Melting temperature and pressure are referred to together as the melting point. During the transition (which is also known as “thawing”), the temperature remains constant and all the heat supplied is invested in the change of the aggregate state as enthalpy of fusion. For example, a water/ice mixture at normal pressure has a temperature of 0 °C. The opposite of melting is solidification.