In chemistry, materials science, and physics, the solidus is the locus of temperatures (a curve on a phase diagram) below which a given substance is completely solid (crystallized). The solidus is applied, among else, to metal alloys, ceramics, and natural rocks and minerals.
The solidus quantifies the temperature at which melting of a substance begins, but not necessarily the substance is melted completely, i.e., the solidus is not necessarily a melting point. For this distinction, the solidus may be contrasted to the liquidus. The solidus and liquidus do not align or overlap in all cases. If a gap exists between the solidus and liquidus, then within that gap, the substance consists of solid and liquid phases simultaneously (like a “slurry”). Such is the case, for example, with the olivine (forsterite–fayalite) system.
In eutectic mixtures the solidus and liquidus temperatures are identical, i.e., the mixture melts completely at one temperature, the eutectic point.
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This information originally retrieved from http://en.wikipedia.org/wiki/Solidus_(chemistry)
on Wednesday 3rd August 2011 9:29 pm EDT
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