Guide
Match the material to the motor duty cycle
BLDC motors, traction motors, pumps, fans, robotics joints, and industrial servos each impose different thermal and magnetic loads. NdFeB offers high energy density, bonded NdFeB can simplify geometry and pole patterns, ferrite can reduce rare-earth exposure, and SmCo can support harsh high-temperature environments when the application justifies it.
Watch for hidden demagnetization risk
Peak temperature, reverse fields, short-circuit conditions, rotor geometry, magnet thickness, and air gap can all affect the operating point. A grade that works in a sample motor may not survive worst-case production, duty cycle, and end-of-life conditions.
Build the sourcing plan into the design
Programs with Dy/Tb-containing grades can review HRE-Free equivalents without treating HRE-Free as a design compromise. The review should compare same-performance options, qualification path, licensing exposure, tariff exposure, and the number of qualified production routes available at target volume.