Technical Highlights
High Energy Density → 35-52 MGOe magnetic output for compact, high-torque motors
Demagnetization Resistance → Hcj up to 45 kOe (AH grade), critical for 30,000 RPM+ operation
GBD-Enhanced HRE → Dy/Tb grain-boundary diffusion achieves 230°C stability
Low-Loss Embedded Design → Halbach array integration reduces eddy current by 40%
Performance Advantages
97.5% Peak Efficiency → Silicon steel pairing minimizes hysteresis loss
Weight-to-Power Ratio → 9.6 kW/kg (vs. 3.2 kW/kg in ferrite motors)
Military-Grade Thermal Range → -50°C~230°C (AH grade for aerospace applications)
Future Trends
Axial Flux Revolution → 70% thinner than radial motors (e.g., YASA model)
Modular E-Axles → Enables 4-motor torque vectoring in premium EVs
Post-RE Reduction → Dy-free NdFeB prototypes show 180°C capability
Application of NdFeB in Traction Motors
NdFeB (Neodymium Iron Boron) permanent magnets, renowned for their exceptionally high magnetic energy product and superior coercivity, have become the core material in modern electric vehicle (EV) traction motors. As traction motors evolve toward higher speeds and greater power output, the magnet mounting configuration has transitioned from surface-mounted to embedded rotor designs. Through optimized magnetic circuit design and multi-pole magnet arrangements, the motor’s energy conversion efficiency is significantly enhanced, achieving higher power density, faster dynamic response, and superior lightweight characteristics.
The outstanding magnetic properties of NdFeB contribute to an optimized torque output curve and energy efficiency, with motor efficiency typically exceeding 97%. Additionally, the high magnetic energy product of NdFeB enables more compact and lightweight motor designs, meeting the stringent requirements of EVs for extended range and space efficiency. With the adoption of advanced topologies such as axial-flux motors, further reductions in size and weight are expected, offering greater advantages in hybrid and multi-motor distributed drive systems.
Conventional NdFeB magnets were limited to operating temperatures of around 80°C. However, recent breakthroughs in grain boundary diffusion (GBD) technology and the incorporation of heavy rare-earth elements (Dy, Tb) into the NdFeB lattice have dramatically improved intrinsic coercivity (Hcj), enabling high-temperature applications. Currently, commercial NdFeB magnets can reliably operate at 150°C (SH grade) and 180°C (UH grade), while laboratory-developed ultra-high-temperature grades (AH grade, 230°C) have also achieved success.
It is evident that NdFeB will remain the cornerstone of traction motor technology for the next 10 to 20 years, continuing to drive advancements in motor efficiency and power density.