High efficiency, low cost, high-temperature nanocomposite soft magnetic materials for vehicle power electronics

Opportunities exists to use high pressure gas atomization (HPGA) to replace currently used, expensive melt-spinning for making soft magnetic nanocomposite alloy powders containing high moment -CoFe phase. The key to this development is to design advanced soft nanocomposite materials for small, lightweight vehicle power electronics, by using an innovative low cost HPGA approach to obtain high induction, high temperature soft magnetic nanocomposite materials that have low magnetostrictive coefficients and eddy current, and high operating temperature over conventional ones. The proposed project will (1) develop high permeability, large induction, low-loss (hysteretic/eddy current) soft magnetic nanocomposite materials containing high moment -CoFe, which are capable of operating at high temperatures and high frequencies; and (b) improve mechanical properties and corrosion resistance of these materials with weight reduction and magnetic performance enhancement at higher operating temperatures as a result of reduction in powder size, which can be achieved by lowing annealing temperature for crystallization process, because mixtures of amorphous and nanocrystalline powders can be directly obtained by HPGA as compared to the conventional melt-spinning process that forms amorphous ribbons. In this Phase I study, Aegis Technology has demosnttrated a novel class of CoFe-based nanocomposite soft magnetic materials, and developed an innovative cost-effective approach to produce this class of high permeability, large saturation, and induction, low-loss (hysteretic/eddy current) soft magnetic nanocomposite materials with high operating temperatures. The Phase I research covered material design, processing development, chracterization and protoyping, with an aim to identify the underlying technical issues that govern the fabrication and performance of this novel class of soft magnetic nanocomposites. In Phase II more detailed research toward product development will be carried out. The composition design and processing parameters will be further optimized to meet targeted magnetic performance at both room and elevated temperatures. A cost-effective fabrication process for the production of nanocomposite cores established in Phase I will be scaled up. Some typical prototypes of inductors will be designed, built and tested, which will pave the way for potential commercialization of proposed soft materials. The successful development of the high permeability, high induction soft magnetic nanocompsoite materials with low-loss (hysteretic/eddy current) and high operating temperatures/frequencies will enable the production of high-efficiency small/lightweight passive inductor. This proposed soft magnetic nanocomposite will lay the foundation for next-generation small/lightweight passive inductors that would have much improved magnetic performance in both induction and application temperatures. Applications for these new magnets are expected to include electric power generation and distribution for use in electric drive vehicles, aircraft, space vehicles, and weapons power systems. Soft magnetic materials with the capabilities of high temperature and high frequency operation would enable simpler, more efficient designs for many military and commercial applications.