Magnequench Technical Resource Website, a subsite of

Factors Affecting Magnet Aging

Permeance coefficient (PC) value of magnet

  • Magnets with higher PC values have either same diameter with longer length or same length with smaller diameter.
  • Magnets with higher PC values have better self demagnetization characteristics and hence lower aging loss.

Density of magnet

  • To achieve higher density, magnets are pressed with higher tonnage. This causes additional powder fracturing which creates fresh surfaces.
  • Exposed fresh surfaces lead to higher aging loss.

Saturation of magnet

  • Insufficient saturation of the magnet results in
    • Reduced squareness of hysteresis loop
    • Lower Hci
  • Reduced squareness and lower Hci leads to higher aging loss.