Today aluminum worldwide producers spend huge amounts of money for processing of rejected products, which inevitably appear in the casting process of complex multicomponent alloys in the form of large round or rectangular ingots.

The technology of aluminium ingot liquid core electromagnetic stirring during the process of casting allows to solve all problems arising in the process of manufacturing the products with high added value, including the alignment of the chemical composition of the ingot structure throughout the cross section and reduced rejection rates. A distinctive feature of electromagnetic stirring technology, developed by UniMet LLC, is the flexibility of options depending on the type of alloy, relatively low energy consumption, small size, easy installation.

Aluminium ingot liquid heart MHD stirring (LHMS) is based on running electromagnetic field, created by a couple of stirrers from both sides of the ingot. They provide control of heat and mass transfer by stirring the liquid heart during the process of casting. This allows solving all tasks arising during the process of value added products manufacturing. This includes homogenizing of chemical and structural composition along the whole ingot volume with a dramatic defects reduction. Main peculiarity of the electromagnetic stirrer technology developed by UniMet is settings flexibility depending on the type of alloy, relatively low energy consumption, compact size, easiness of installation.

LHMS stirrers are installed within the existing casting pit volume from both sides of the ingot. Inductors installation does not require redesign of existing casting machine or mould, and requires only installation of a support frame over the shaft, which allows fixing the inductors and adjust their position. LHMS stirrers can be installed at multi strand casting pits, while one inductor can influence on two ingots simultaneously.

LHMS advantages

  • Ingot cycle time reduction up to 25%;
  • Defect products volume reduction up to 30-40%;
  • Chemical composition improvement along the whole ingot cross section;
  • Control over the heat and mass transfer within ingot liquid heart;
  • New alloys manufacturing possibility;
  • Structural composition improvement along the whole ingot cross section;
  • Economical effect could be up to 3 mln. USD/year per one mould casting pit.

Economical benefits

A distinctive feature of electromagnetic stirring technology, developed by UniMet, is the flexibility of options depending on the type of alloy, relatively low energy consumption, small size, easy installation. The calculation presented in the table below was done based on one mould casting pit with capacity of 30 000 ton/year, mould size 1,5 x 0,6 m, casting speed – 60 mm/min, 7xxx alloys series, rejection - 4%. It is necessary to take into account that calculation is done for the casting pit with one mould. During simultaneous casting of several ingots at a time the economical benefit with the LHMS technology implementation will be higher.

 Combination of the Customer's problems
 Standard calculated net profit (USD) $5 979 646
case 1  net profit loss caused by capacity reduction (USD) $996 608
case 2  rejection remelting loss and the resulting lost income $334 860
case 3  customers reclamations USD ?
   business reputation PRICELESS
case 4  value added net profit with new alloys (USD) $1 993 215
 in summary the potential benefit is $1 331 468
 total potential benefit per mould with new alloys also is $3 324 683