Ingot

Non-metallic and semiconductor materials prepared in bulk form may also be referred to as ingots, particularly when cast by mold based methods.

Ingots are generally made of metal, either pure or alloy, heated past its melting point and cast into a bar or block using a mold chill method.

The boules may be either semiconductor (e.g. electronic chip wafers, photovoltaic cells) or non-conducting inorganic compounds for industrial and jewelry use (e.g., synthetic ruby, sapphire).

[4] During colonial times the brass and bronze industries were almost non-existent because the British demanded all copper ore be sent to Britain for processing.

A variety of designs exist for the mold, which may be selected to suit the physical properties of the liquid melt and the solidification process.

Molds may be either solid "massive" design, sand cast (e.g. for pig iron), or water-cooled shells, depending upon heat transfer requirements.

A crack or void formation occurs as the liquid to solid transition has an associated volume change for a constant mass of material.