moltenstate

Moltenstate refers to the liquid phase of a substance produced by heating above its melting point. In the molten state, particles have enough kinetic energy to overcome solid-state bonds and flow past one another. For pure crystalline materials, melting occurs at a specific temperature; for impure substances and alloys, melting happens over a range between the solidus and liquidus temperatures. Some materials, such as certain glasses, soften gradually rather than melting abruptly because of their amorphous structure.

In the molten state, properties such as viscosity, surface tension, and reactivity are strongly temperature dependent. Molten metals have lower viscosity than at room temperature, enabling processes like casting and alloying. The molten form is typically highly reactive and prone to oxidation, so processing often occurs in controlled atmospheres and with protective crucibles made from refractory materials. Polymers and ceramics also melt or soften for shaping, with melt rheology playing a crucial role in determining final properties after solidification.

Applications include metal casting and alloy production, welding and additive manufacturing, glassmaking, and polymer processing. Temperature control is critical to achieve desired flow and microstructure, which in turn affect strength, toughness, and other performance characteristics. Industrial handling of molten materials requires specialized equipment, including furnaces or induction heaters and refractory containment, along with safety measures to manage high temperatures and hazardous fumes.

See also: phase transitions, melting point, phase diagram, castings, glass transition.