What is high temperature SmCo magnet ?
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- Issue Time
- May 28,2020
High
temperature SmCo
magnets that can withstand temperatures of 500°C and
550 °C
Many
key devices in the aerospace and other fields, such as aircraft motors and
generators, microwave function tubes, magnetic bearings and inertial navigation
devices, require high-performance high-temperature permanent magnet
materials.
Among
the existing permanent magnet materials, the strongest NdFeB magnet has the highest room temperature performance, but its
Curie temperature is 312 °C, and
the maximum working temperature is usually not more than 250 °C;
the
Curie temperature of AlNiCo magnet is 850 °C ,
The maximum operating temperature can reach 520 °C, but
the coercive force of the magnet is very low (< 145 kA / m), so it can not manufacture small and light components; SmCo magnet has a high Curie temperature (750 ~ 920 °C),
Moreover,
it has strong magnetocrystalline
anisotropy and high coercivity at room temperature (> 1990 kA / m), which is
the first choice for high temperature permanent magnet material.
The
main reason why the traditional 2:17 SmCo magnet is not suitable for high temperature applications is
that its coercive force decays rapidly with increasing temperature (coercive
force temperature coefficient β ≈-0.30% / °C). By
adjusting the alloy composition and heat treatment process of the traditional
2:17 type SmCo magnet , the microstructure and microcomposition
inside the material are controlled to reduce the temperature coefficient of the
coercive force of the material and increase the use temperature. In the end, we successfully made a 2:17 type SmCo high temperature magnet that can be applied at 500 ° C and 550 ° C.