Overview
IEC TR 62517:2009 - "Magnetizing behaviour of permanent magnets" is a technical report from the International Electrotechnical Commission (IEC) that documents how modern permanent magnets respond to applied magnetizing fields. The report explains the relationship between the externally applied field and the internal field acting in the magnet, describes the typical initial (virgin) magnetization states, classifies magnet types by coercivity mechanism, and compiles recommended internal magnetizing field strengths for complete saturation.
Key topics
- Internal vs. applied field: treatment of the effective internal magnetic field Hint = Happl − Hdemag (including the role of the demagnetization coefficient N and polarization J) and implications for magnet assembly magnetization.
- Initial magnetization state: description of the thermally demagnetized (virgin) state after final heat treatment and methods to reset magnets (e.g., heating above the Curie temperature for ferrite and RE‑Fe‑B; full heat treatment for SmCo).
- Coercivity mechanisms and magnetizing behaviour:
- Nucleation-type (sintered ferrite, RE‑Fe‑B, SmCo5) - typical magnetization curves and approach to saturation.
- Pinning-type (carbon steel, Sm2Co17) - distinct magnetizing response and reversal behaviour.
- Single-domain particle type (nano-crystalline RE‑Fe‑B, Alnico, Cr‑Fe‑Co) - behaviour of single-domain particles and implications for magnetizing process.
- Practical magnetizing recommendations: a comprehensive table of recommended internal magnetizing field strengths to reach complete saturation from the post‑heat‑treatment state (report includes guidance rather than a single simple multiplier rule).
- Magnetization pulse considerations: guidance about pulse magnetization (commonly used via capacitor discharge), including pulse-duration effects and typical penetration guidance (pulse durations of about 5–10 ms are generally sufficient for complete penetration of many blocks).
Applications
IEC TR 62517:2009 is practical for:
- Design and optimization of magnetizing coils and pulse generators for production magnetization.
- Assembly-level magnetization planning (magnetize-after-assembly best practice to reduce handling risks).
- Quality control and test-lab procedures for verifying saturation and acceptable magnetizing fields.
- Failure analysis (understanding demagnetization, reversal and remanence behaviour).
- Material selection and process specification for manufacturers of motors, sensors, actuators, and magnetic assemblies.
Who should use it
- Magnet engineers and designers
- Manufacturing and assembly engineers
- Test laboratories and R&D teams working with RE‑Fe‑B, SmCo, ferrite, Alnico and related magnet materials
- Standards developers and technical procurement specialists
Related standards
Keywords: IEC TR 62517:2009, magnetizing behaviour, permanent magnets, coercivity mechanisms, nucleation, pinning, single domain, internal magnetizing field, saturation, RE‑Fe‑B, SmCo, ferrite, Alnico, pulse magnetization.