Soft Magnetics

Powder Metallurgy technology is used in the production of soft-magnetic materials and permanent magnets.  The PM process permits production to final shape with a minimum of secondary finishing, while at the same time achieving the desiraable magnetic properties.

Types of compositions used for soft-magnetic pressed to shape include:

PURE IRON - High saturationinduction with good maximum permeability but low electrical resistivity make this material ideal only for DC magnetic applications such as pole pieces, magnetic clutches, etc.

IRON-PHOSPHOROUS ALLOYS - From 0.45P-0.80P.  Addition of phosphorous improves saturation induction and maximum permeability and lowers coercive force, and increases electrical resistivity, thus reducing AC core losses.  They are used in both AC and DC applications.

ALLOY - 50% Fe & 50% Ni - Characteristics of high initial and maximum permeability and the lowest coercive force of teh commercially available soft-magnetic alloys.  These materials are used in magnetic amplifiers, relays, motors and generators.

 

The MPIF standard includes four characteristic properties of soft-magnetic materials, measured under DC magnetization conditions.  These properties are illustrated in teh graph above and described below:

  • Bm is the maximum magnetic induction measured in the material at a specific magnetizing field.

  • Br is the magnetic induction that remains in the material after the magnetizing field has been reduced to zero from the maximum applied field

  • Hc is the coercive field strength or magnetic field remaining in the material when the magnetic induction has been decreased to zero.
  • µmax

 

If you would like additional information on PM magnetic materials or want to discuss a particular application you may have, please contact us at info@ascosintering.com.