The effects of Si addition on microstructure and magnetic properties of permalloy strips fabricated by melt drag casting

Permalloy strips with 200 mm width were successfully fabricated by melt drag casting, and their microstructure and consequent magnetic properties were analyzed as a function of Si content. The effective permeability went through a maximum value for 2% Si-containing permalloy strips and then decreased with increasing Si content. Increasing Si content enlarged grain size, which improved permeability. However, addition of Si above 2% caused the formation of Ni3Fe ordered phase, which drastically reduced permeability in 5% Si-added permalloy strips.