2040 – 04 – Finding Melting Points

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The temperature where a metal changes from a solid to a liquid is its melting point.
The opposite of the melting point, when a metal changes from a liquid to a solid, is the freezing point. Pure metals have freezing and melting points that are often very close in temperature.

To picture this idea, imagine an ice cube is your pure metal. Ice melts and freezes at 0 degrees Celsius. If your ice cube is at negative ten degrees Celsius, then you heat it up ten degrees, it will melt. If it’s at 4 degrees Celsius, and you cool it down to 0 degrees Celsius, it will re-freeze.

For pure metals, the freezing and melting points are the same. Pure metals need extra energy to melt from a solid to a liquid. This extra energy is referred to as fusion.

Because they combine a variety of materials, metal alloys melt differently than pure metals. The process is much slower and has different terminology:

– The liquidus marks the point at which the alloy is entirely melted
– The solidus marks the point at which the alloy begins to melt.