Physics of Magnetism

14

Soft-Magnetic Materials

14.1. INTRODUCTION

Soft-magnetic materials are mainly used in magnetic cores of transformers, motors,
inductors, and generators. Of prime importance for applications in cores are a high per­
meability, low magnetic losses, and a low coercivity. Definitions of all these quantities are
given in Fig. 14.1.1. Other important factors, in particular for large electrical equipment,
are a high magnetic flux and low costs.
Unalloyed iron, silicon–iron, and aluminium–iron alloys are widely used in high-
power machines. However, for some critical applications, more expensive materials are
more suitable. Examples of such materials are Permalloy, Supermalloy, various types of
amorphous alloys and nanocrystalline alloys. Several important soft-magnetic materials
will be discussed below.

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