High Temperature SmCo Arc Magnets are engineered for synchronous motors, high-speed actuators, and sensor assemblies operating in extreme thermal and oxidative environments. Fabricated via powder metallurgy-combining jet milling, 2-Tesla magnetic field alignment, and solid-state vacuum sintering-these anisotropic segments maintain high intrinsic coercivity at continuous operating temperatures up to 350°C. SmCo retains structural and magnetic stability without catastrophic flux degradation under high thermal stress, eliminating the need for heavy rare-earth additions of Dysprosium or Terbium in standard specifications.
Technical Specifications
|
Parameter |
Specification Range |
Test Standard / Notes |
|
Material Grades |
SmCo5 (16–24 MGOe), Sm2Co17 (22–33 MGOe) |
IEC 60404-8-1 / ASTM A977 |
|
Max. Operating Temp. |
250°C to 350°C |
Sm2Co17 configurations optimized for upper thresholds |
|
Remanence (Br) |
8.5 – 11.5 kGs (0.85 – 1.15 T) |
Measured at ambient temperature (20°C) |
|
Intrinsic Coercivity (Hcj) |
15 – 30 kOe (1190 – 2387 kA/m) |
Resists thermal demagnetization at peak load |
|
Max. Energy Product ((BH)max) |
16 – 33 MGOe (128 - 263 kJ/m³) |
Room temperature nominal value |
|
Temp. Coefficient of Br |
-0.035% to -0.045% /°C |
Linear thermal drift range (20°C to 300°C) |
|
Dimensions (Arc) |
Outer Radius: 15 - 150 mm, Thickness: 2 - 25 mm |
Built strictly to customer CAD specifications |
|
Standard Tolerances |
±0.05 mm (Ground finish) |
Achieved via diamond wire-sawing and surface grinding |
|
Magnetization Direction |
Diametral, Radial, Parallel across arc |
Configured via custom pulse-magnetization fixtures |
Key Features
High Hcj preserves magnetic flux output at continuous temperatures up to 350°C, preventing rotor lock-up or instrumentation signal drift.
Alloy matrices containing over 60% Cobalt resist environmental corrosion without requiring electroplated barriers that risk blistering under high thermal cycling.
Predictable, linear flux variations relative to temperature streamline thermal compensation in aerospace feedback loops and servo systems.
Microstructures structured in 2-Tesla fields deliver targeted vector orientation for concentrated air-gap magnetic flux density.
Applications
Aerospace Actuators: Brushless DC motors and valve control loops operating within engine compartments and environmental control systems.
High-Speed Motors: Centrifugal compressor drives and micro-turbine generators running at >50,000 RPM where rotor temperatures exceed Neodymium limits.
Downhole Oil & Gas Tools: MWD/LWD (Measurement/Logging While Drilling) telemetry units subjected to downhole temperatures >200°C and intense shock loads.
Defense Electronics: Traveling-wave tubes (TWTs), ring laser gyroscopes, and radar magnetrons requiring rigid magnetic field stability.
Customization
Production executes directly from customer 3D models (STEP/IGES) and 2D manufacturing prints.
Geometry:
Custom inner/outer radii, arc angles (e.g., 30°, 45°, 60°), chord lengths, and axial stacking dimensions, incorporating edge chamfers or wire-cut mounting slots.
Grade Formulation:
Targeted composition adjustments between SmCo5 and Sm2Co17 variants to balance energy product against thermal limits.
Magnetization Patterns:
Single-pole arc orientations, multi-pole radial layouts, or custom skew configurations designed to minimize cogging torque in synchronous machines.
Surface Finishes:
As-sintered, rough ground, or precision diamond-ground finishes held to tight surface roughness thresholds (Ra < 0.8 um).
Manufacturing & Quality Control
Manufacturing follows strict rare-earth powder metallurgy protocols to ensure structural integrity and batch-to-batch repeatability.
Alloy Melting & Atomization: Vacuum induction melting (VIM) paired with strip casting to achieve uniform chemical distribution across the ingot.
Jet Milling & Pressing: Micron-scale pulverization via jet milling, followed by wet or dry magnetic compaction under a 2-Tesla alignment field to maximize remanence.
Sintering & Heat Treatment: Solid-state reaction sintering in high-purity argon furnaces, followed by precise solution and aging steps to precipitate stabilizing phases in Sm2Co17 matrices.
Precision Machining: Diamond grinding, slicing, and wire-EDM executed with water-miscible coolants to prevent micro-cracking in the brittle material. Inspection utilizes 3D optical comparators and CMM equipment.
Magnetic Testing: 100% hysteresis loop screening via Hysteresis Graph Testers and Helmholtz coils at standard or specified elevated temperatures to verify Br, Hcb, Hcj, and (BH)max.
Packaging & Documentation
Secured inside heavy-duty commercial iron/steel shielding containers to restrict external stray fields below IATA dangerous goods air-transport limits.
Individually separated using high-density closed-cell polyethylene foam and vacuum-sealed anti-static barriers to eliminate chipping and surface oxidation during freight transit.
Each consignment ships with a Certificate of Analysis (CoA) containing individual batch hysteresis curves, dimensional inspection sheets, material composition reports, and MSDS.
FAQ
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