Improvement of magnetic properties of electrical steels using a surface diffusion technique

Abstract

The preceding paper described the general process by which the magnetic properties of electrical steels can be improved by a surface diffusion technique. This paper describes detailed effects of adding aluminium or silicon to non-oriented and grain-oriented silicon-iron. The addition of silicon proved more difficult and surface porosity tended to increase the power loss of grain-oriented steel whereas a paste containing aluminium powder was effective on all the materials although it was found that the powder size was critical. A reduction of 10% at 1.5 T in well oriented silicon-iron was achieved using the aluminium powder and an improvement in stress sensitivity of the magnetic properties also resulted.