Samarium Cobalt Magnets (SmCo)
Sintered Samarium-Cobalt magnets (also known as SmCo) date back to the early 1970s and were the first example of rare earth magnets.
They are composed of a Samarium and Cobalt alloy. They are generally less powerful than Neodymium magnets but have two considerable advantages:
- excellent thermal behaviour
- high resistance to corrosion
These two characteristics allow the magnetic properties to diminish less as the temperature rises compared to Neodymium, together with the possibility of using them without the need for coatings or surface treatments.
They are suitable for applications requiring high thermal stability and corrosion resistance.
They reach their maximum performance when used on:
- Brushless motors in the harshest conditions
- Constant output generators, regardless of the operating temperature
|SAMARIUM – COBALT|
|Recoil permeability (µr)||–||1.03||1.05|
|Saturation field||kOe||> 25||> 50|
|Electrical resistivity||_ Ω cm||50||80|
|Compressive strength||N/mm2||~ 850||~ 800|
|Flexural strength||N/mm2||100 – 150||100 – 150|
|Hardness – Vickers||HV||~ 600||~ 600|
|Specific heat||kcal/kg.°C||0.08 – 0.09||0.08 – 0.09|
|Thermal conductivity||kcal/m/hr/°C||8||8 – 9|
|Coeff. of thermal expansion //||10-6/°C||7||10|
|Coeff. of thermal expansion_||10-6/°C||12||12|