Ultra-high Temperature Samarium-cobalt Magnet

Overview

Product Specifications

Material Composition:

Alloy Type: Sm2Co17 (2:17 series) with additives (Fe, Cu, Zr) for enhanced thermal stability.

Key Elements: 25% Samarium, balance Cobalt + transition metals.

Magnetic Properties

Energy Product (BH)max: 26–34 MGOe (208–272 kJ/m³).

Residual Induction (Br): 1.02–1.18 T (10,200–11,800 Gauss).

Coercive Force (Hc): 2,400–2,800 kA/m.

Temperature Performance:

Operating Range: -65°C to 550°C (short-term peaks).

Reversible Temp Coefficient (αBr): -0.03%/°C.

Physical Properties:

Density: 8.3–8.5 g/cm³; Tensile Strength: 40–85 MPa.

Product Grades

Ultra-high temperature SmCo magnets are classified by remanence (Br) and thermal stability:

Standard High-Temp Grades:

YXG-26: Br ≥1.02 T, stable up to 350°C (typical for aerospace motors).

YXG-30: Br ≥1.15 T, stable up to 450°C (e.g., oil drilling sensors).

Ultra-High-Temp Custom Grades:

Zhiyu UHT-550: Br ≥1.18 T, optimized for 550°C (hydrogen compressors, satellite systems)

SDM HT-500: Linear B-H curve up to 500°C (defense gyroscopes)

Coatings

While SmCo magnets inherently resist corrosion, specialized coatings are available for niche applications:

Parylene: For medical/MRI components to prevent biocompatibility issues

Nickel (Ni): Enables soldering for PCB integration (e.g., 5G communication devices)

Gold/Zinc: Low-resistivity coatings for high-frequency electronics (10–40 GHz)

Epoxy Cladding: Mechanical protection in industrial settings (e.g., turbine sensors)

Applications

These magnets are pivotal in industries demanding reliability under extreme conditions:

Aerospace/Defense: Satellite orientation systems (drift <10⁻⁵°/hr), missile guidance, jet engine sensors (FAA-compliant)

nergy: Downhole drilling sensors (175°C+), wind turbine generators

Medical: MRI gradient coils (0.1 T/m precision), surgical robotics

Industrial: High-speed motors, hydrogen compressors, 5G infrastructure

FAQs

How do ultra-high-temp SmCo magnets compare to NdFeB?

SmCo outperforms NdFeB in thermal stability (NdFeB degrades above 150°C) and corrosion resistance, but NdFeB has higher Br at room temp

Can these magnets be machined post-sintering?

Yes, but only with diamond tools or EDM due to brittleness (flexural strength <2 MPa√m)

Why are they expensive?

High samarium/cobalt content (~$40–80/kg) and complex multi-stage heat treatments drive costs

Do they require adhesives for assembly?

Epoxy bonding or mechanical clamping is recommended to avoid stress fractures

Are custom shapes available?

Yes, manufacturers offer tiles, rings, and multi-segment stacks (e.g., Zhiyu’s radial magnets for motors)