Coatings will limit contamination in crucibles

According to Morgan Advanced Materials, contamination of molten metals by crucible materials during melting operations can be minimised by coating the interior surface of the crucible. This helps to prevent reactions between the metal and the crucible while acting as a diffusion barrier to reduce impurities. PRO and STAR Coatings have been formulated to reduce impurities and so optimise the quality of the molten metal and the final cast product.

PRO Coating is a thin covering which significantly reduces impurities when melting and holding pure alloys. It also stops dross build-up, making cleaning easier. PRO Coating can be mixed with water and applied to the crucible with a brush. It can also be used as a mortar to repair areas that may have been damaged or chipped, maximising crucible life. Chemically bonded and consisting of sintered alumina, PRO Coating can be used up to a melting temperature of 1,600°C (2912°F) making it ideal for use with high-purity aluminium, aluminium alloys and precious metals.

Designed specifically for melting pure aluminium (Al5N), Morgan’s STAR Coating can be applied onto all clay-bonded crucibles and carbon bonded by spraying. It is then fired to ensure a good bond. Consisting primarily of Boron Nitride with an oxide bond, it can be used up to a melting temperature of 1,000°C (1832°F). STAR Coating prevents contamination of the aluminium and dross build-up in the crucible, ensuring the highest purity of metal when melting aluminium and aluminium alloys.