Permendur is the topic of this article, which will provide readers with information about the meaning, properties, grades, and more regarding Permendur.
Meaning of Permendur
Permendur is a soft magnetic alloy with high saturation magnetic induction. It is primarily composed of iron (Fe), cobalt (Co), and vanadium (V).
| Chemical Composition: It typically contains iron (balance), cobalt (49.0~51.0%), vanadium (0.80~1.80%), and other trace elements such as carbon (C≤0.04%), manganese (Mn≤0.30%), silicon (Si≤0.30%), phosphorus (P≤0.020%), sulfur (S≤0.020%), copper (Cu≤0.20%), and nickel (Ni≤0.50%).
| Physical Properties: It has a high saturation magnetic induction (up to 2.4T), a high Curie point (980℃), and a large magnetostrictive coefficient (60~100×10-6). These characteristics enable Permendur to respond excellently in a magnetic field. However, it is prone to oxidation in high-temperature environments, making appropriate protective measures necessary to extend its lifespan.
Advantages of Permendur
Due to its high saturation magnetic induction, it can significantly reduce the size when manufacturing motors of equivalent power, and it can generate a strong attractive force with the same cross-sectional area when used as an electromagnet. The high Curie point allows this alloy to work at higher temperatures where other soft magnetic materials have completely demagnetized, maintaining good magnetic stability.
The large magnetostrictive coefficient makes it highly suitable as a magnetostrictive transducer, providing high output energy and efficiency.
Disadvantages of Permendur
| High cost: It is expensive to produce, limiting its use in some cost-sensitive areas.
| Poor machinability: It has relatively poor machinability, increasing its manufacturing costs and processing difficulties.
Grades of Permendur
| Grade | Resistivity | Curie Temperature | Coercivity (Hc) | Magnetic flux density | |||
|---|---|---|---|---|---|---|---|
| 1J22 | 0.4 μΩ·m | 980℃ | ≤ 1.4 Oe | B₄₀₀ | B₂₄₀₀ | B₄₀₀₀ | B₈₀₀₀ |
| ≥ 17 kGs | ≥ 21 kGs | ≥ 22 kGs | ≥ 23 kGs | ||||
| 1J27 | 0.19 μΩ·m | 980℃ | ≤ 1.8Oe | B₈₀₀ | B₄₀₀₀ | B₁₂₀₀₀ | B₁₆₀₀₀ |
| ≥ 15 kGs | ≥ 18 kGs | ≥ 21.2 kGs | ≥ 22.1 kGs | ||||
Machinability of Permendur
Although it has excellent magnetic properties, its machinability is relatively poor, so appropriate measures need to be taken during processing to ensure that the material’s performance and shape meet requirements.
It is not only difficult to machine, but the significantly high saturation magnetostrictive coefficient (up to 70 × 10-6) means that processing stress can greatly deteriorate its magnetic properties. To improve the degradation of magnetic properties, it is necessary to coat its surface with alumina or magnesia powder as an insulation layer after processing, and perform heat treatment (annealing) at 850℃ in a hydrogen environment.
Applications of Permendur
Due to its unique magnetic properties, it has a wide range of applications in multiple fields:
| Aerospace: Due to its high melting point and excellent high-temperature strength, Permendur is widely used in manufacturing high-temperature structural components for aircraft and satellites, capable of withstanding extreme temperature variations and mechanical stresses.
| Electronics: The exceptional electrical properties of the material make it an ideal material for manufacturing high-grade capacitors and electron tubes, which play critical roles in electronic devices.
| Electronic Instruments: In sensors that require precise sensing and high stability, its low temperature coefficient and high magnetic permeability make it an ideal material.
Magnet Manufacturer
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