Montaigne 2 applies to him the phrase of Horace: "Liquidus puroque simillimus amni."
All mixtures whose temperature lies above the line ACB are wholly liquid, hence this line is often called the "liquidus "; all mixtures at temperatures below that of the horizontal line through C are wholly solid, hence this line is sometimes called the " solidus," but in more complex cases the solidus is often curved.
At temperatures between the solidus and the liquidus a mixture is partly solid and partly liquid.
We can then draw a continuous surface through the summits of all these ordinates, and so obtain a freezing-point surface, or liquidus; points above this surface will correspond to wholly liquid alloys.
How would you define liquidus? Add your definition here.