SMC are insulated iron powders intended for use in replacement of electrical steel sheets in electromagnetic devices subjected to time varying magnetic fields. Manufactured using the powder metallurgy route with its choice of processing conditions, a range of SMC materials with adequate final properties can be achieved. For instance, two types of SMC powders that differ in composition and in processing route are herein described. One is an iron-resin composite material, which requires die wall lubrication during compaction and a low temperature curing in air to crosslink the resin and achieve high strength (ATOMET EM-1). The other is an iron/dielectric composite material in which the dielectric acts as a lubricant during the compaction as well as an electrical insulator after a moderate temperature heat treatment (ATOMET EM-2). Lately, developmental work led to improvements in both types of SMC materials, which are presented in this paper. The properties as well as the processing aspects are discussed, especially the compaction and heat treatments.
展开▼
