At present, there are five kinds of magnetic materials for your options in accordance with the
magnetic force from weak to strong ,the order is the rubber magnet, ferrite magnet, Alnico magnet,
smco magnet,NdFeB magnet.
The following table briefly described the characteristics of each type of material to help you choose
a suitable magnet.
Selecting a grade is the next step, once you have decided which permanent magnet material is best for your application.
Generally, a grade indicates the Maximum Energy Product of a magnet. For instance, Grade 32 implies the (BH)max is about 32 MGOe.
A higher grade of permanent magnet has a better performance. However, higher grade is usually associated with a higher cost.
Taking sintered Nd-FeB magnets as an example, the price of Grade 45 is twice and even more of that of Grade 33.
Other property parameters, such as Br and Hci,
also need to be considered in selecting a grade. One way to select the suitable grade for your application is "trial and error". You can purchase the several magnets with different grades (some suppliers have these magnets available on their shelves) and try each grade until you find one right for your application.
1, selected samarium cobalt magnets in accordance with the needs of different magnetic properties
2, If you want samarium cobalt permanent magnets used in high temperature, you need to consider the magnetic properties of two key parameters: reversible temperature coefficient (such as Br) and the intrinsic coercive force Hcj. Reversible temperature coefficient is a measure of permanent magnetic materials in the temperature changes in the parameters, when the temperature back to the beginning of temperature, magnetic properties of permanent magnetic materials can be reversible back to a state of the magnetic properties of the beginning. However, the smaller the temperature coefficient, the magnetic properties of a corresponding decline. At the same time, with the temperature changes, magnetic properties of permanent magnetic material is also irreversible changes as the irreversible loss. Higher intrinsic coercivity will reduce the irreversible loss.
3,The design of samarium cobalt permanent magnet in the application also need to consider if the designed size of the permanent magnet is appropriate. In general, as a result of the permanent magnet SmCo demagnetization curve for the near-linear, and the remainder of magnetic induction Br and coercive force Hcb is similar, and therefore the work of point (Pc value) should be selected in the vicinity of the largest energy product, one can make full use of magnetic energy, on the other hand, can be cost-effective.
4, Samarium cobalt permanent magnet is a function of the material should not be used as structural material, and therefore should not have the same requirements of tolerance in size and structure.
5, Samarium cobalt permanent magnet has a strong corrosion resistance, and therefore does not require surface treatment.
本文转自：China Industry News
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