UniMet Company has developed the revolutionary technology that provides increase of large rectangular aluminium ingots (slabs) quality by means of crystallization process control in the liquid heart especially while casting alloys 2xxx, 5xxx, 7xxx series for airspace and automotive industries.
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 thus organizing more than 50 different types of flows. 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 can be installed at multi strand casting pits, while one inductor can influence on two ingots simultaneously.
- Slab casting cycle reduction up to 40%;
- Casting speed improvement by 85%;
- Chemical composition homogenizing along the whole slab volume that leads to the rejected production decrease during further slabs rolling and milling by 10-90% or completely eliminates it (depending on the type of the alloy). Elimination of the cracks and porosity;
- Reduction of cut off zones (bottom part and top part) by 50% that guarantees significant increase per each casing mold;
- Macro segregation reduction by 55% and mesosegregation reduction by 50% that further excludes the possibility for the defects in the rolled or milled products;
- Possibility to cast new complicated alloys in the shape of large rectangular slabs with the thickness up to 1 meter that was impossible to cast before – AlLi alloys, 2xxx, 5xxx, 7xxx (with the Zn content up to 11%).
Along with the existing technological advantages LHMS has several significant peculiarities compared to competitors’ solutions: settings flexibility depending on the type of alloy, relatively low energy consumption, compact size, easiness for installation and possibility to organize more than 150 types of flows (regimes) in the sump.
By 2016 UniMet Company team developed and patented the LHMS technology, created and approved physical (laboratory) models of technology, produced and tested the industrial sample of the equipment the performance of which confirms LHMS positive influence on end products.