Magnetoforming coils with a long lifetime

03 June 2021 par Super Administrateur

Since 2013, the LNCMI is collaborating with the Toulouse company Bmax / I Cube Research to design magnetoforming coils with long lifetime. Durability is a crucial issue for using electromagnets at an industrial scale, requiring the production of parts in large quantities with extreme precision and at a controlled cost.

To generate very strong magnetic fields, it is necessary to use conductors that combine good electrical conductivity with very high mechanical strength. The LNCMI therefore has its own wire drawing workshop and is able to manufacture itself the conductors necessary for the fabrication of coils which can resist long-lasting magnetic fields (several tens of milliseconds) of up to 98.8 T. It is this expertise that attracted Bmax / I Cube Research, specialist in magnetoforming.

Magnetoforming is a technique that makes it possible to manufacture precise parts with shapes that could not be obtained by other methods at a reasonable costs. The pulsed electromagnets that are designed for this purpose generate very short and strong magnetic field pulses, which induce a current in the metal part to be molded. The part is then projected at very high speed onto a mold which gives it the desired form. This technique is called direct, as opposed to indirect, magnetoforming where a punch is set in motion by magnetic forces, hits the material to be modeled and projects it to the mold. The operation takes place in a few microseconds, and offers a level of precision in the shape of the parts that can meet the expectations of very demanding sectors such as luxury, aeronautics and automotive industry.

However the pulsed electric currents that make this process possible impose enormous magnetic, mechanical and thermal stresses on the electromagnet. The challenge is therefore to produce coils with conductive materials that are sufficiently resistant to sustain these stresses in order to use them on industrial production lines without the need of frequent replacement. Starting with a few hundred pulses realized a few years ago, the LNCMI has therefore optimized electromagnets to withstand more than 30,000 pulses, which corresponds to a 50-times better lifetime. Based on this success Bmax / I Cube Research is now in a position to extend its magnetoforming applications and to conquer new markets. Initially financed by funds of Bmax / I Cube Research, the partnership with the LNCMI was recognized institutionally and has been sponsored as part of local (NEXTMAG project, LABEX NEXT), regional (MAG-IC project, Région Occitanie), national (SIgMA project, ANR) and European (ISABEL project, H2020) projects.

https://www.occitanie-ouest.cnrs.fr/fr/cnrsinfo/des-bobines-de-magnetoformage-grande-duree-de-vie-au-lncmi-un-savoir-faire-unique

Magnetoforming coil – ©LNCMI

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