Longer lasting crucibles for aluminium – Morgan Advanced Materials

High density, clay-bonded, iso-statically pressed crucibles have a high graphite and silicon carbide content.

Morgan Advanced Materials credits ‘a technological advance in materials science’ for new series of crucibles developed by Morgan’s Molten Metal Systems business, claiming these units will last more than 50% longer than previously available crucibles used for aluminium casting.

VAluStar crucibles are highly resistant to oxidation at low temperatures thanks to Morgan’s proprietary glazes, and are particularly well suited to holding aluminium and aluminium alloys in electric resistance furnaces. These high density, clay-bonded, iso-statically pressed crucibles have a high graphite and silicon carbide content.

“We are confident they will add huge value to the aluminium casting industry by reducing downtime and maintenance, therefore increasing productivity,” according to Robin White, general manager.

“Our new family of crucibles has been developed to resist oxidation, which is a common challenge for operators in modern foundries and cast houses. We’ve rigorously tested them against other crucibles in similar operating conditions, and VAluStar has shown that it has a significantly longer lifetime than all other iso-statically pressed crucibles in low temperature applications,” White continued.

To demonstrate the difference, Morgan tested the VAluStar in a 24-hour, aluminium melting and holding application against a conventional iso-statically pressed crucible. The latter needed to be replaced after eight months due to a reduction in thermal conductivity and when top brim cracks occurred due to oxidation.

Meanwhile, the BNS 200 VAluStar crucible’s lifetime was 14 months, exceeding the conventional crucible’s service life by 75% in similar conditions. As well as the extended life of the crucible, thermal productivity was improved by 24%.

Both crucibles were split in half for analysis. While the conventional crucible showed brim oxidation and oxidation nests, the VAluStar crucible only showed a slight brim oxidation, which was caused by the insulation fibre.

VAluStar crucibles are finished with a blue Low Temperature Protection (LTP) coating. Typical metal casting temperature is between 700 and 1000°C.

Pattern range
VAluStar crucibles are available in wide range of shapes and sizes, as per Morgan’s current range of crucible models i.e. A, BU, BN, TP and TBN. The crucible can also be supplied with specialised and patented coatings developed by Morgan Molten Metal Systems to enhance specific properties required in the application.

For further details contact Keegor Meltech on TEL: 011 421 0711 or Eddie Short on 082 460 1593.