Amorphous and Nanocomposite Materials for Energy-efficient Electric Motors

SILVEYRA JM; XU P; KEYLIN V; DEGEORGE V; LEARY AM; MCHENRY M

San Pablo

Congreso; Soft Magnetic Materials Conference SMM22; 2015

In this work we explore amorphous and nanocomposite soft magnetic alloys as candidates for electric motor applications: Fe-based (Fe-Si-B-Nb-Cu), Fe-rich (Fe-Co-Si-B-Nb-Cu), and Co-rich (Co-Fe-Mn-Si-B-Nb) systems. The Co-rich system combines the benefits of low hysteretic and eddy-current losses while exhibiting negligible magnetostriction and robust mechanical properties. The amorphous precursors can be devitrified to form nanocomposite magnets. The superior characteristics of these materials offer the advantage of ease of handling in the manufacturing processing and low iron losses during the motor operation. Co-rich amorphous ribbons were laser-cut to build a stator of a small demonstrator permanent magnet machine. The motor was successfully tested up to ~30,000 rpm. Finite element analyses proved that iron losses of the Co-rich amorphous stator were ~80% smaller than the losses of a Si steel stator in the same motor, at 18,000 rpm (equivalent to an electric frequency of 2.1 kHz). These low-loss soft magnets have great potential for applications into highly efficient high-speed electric machines, leading to size reductions and reducing or replacing rare-earths in permanent magnet motors. More studies evaluating further processing techniques of amorphous and nanocomposite materials are needed.