Powder metal processing is a mass production metal-forming process capable of producing a wide range of magnetic components for both dc and ac applications. For
FIGURE 2.78 Core loss at 60 Hz.
FIGURE 2.79 Core loss at 200 Hz.
dc applications, the designer has the choice of a number of material systems, each with unique properties that can be customized to meet specific part requirements. Care must be taken in the manufacture of the sintered P/M parts to minimize the carbon and nitrogen pickup. By varying the alloying, sintered density, and processing, the resulting magnetic properties cover a broad range of applications.
For ac applications, the P/M industry has developed two families of powders that can be utilized in alternating magnetic fields. The choice between the iron powder-polymer composites and a powder that can be given a low-temperature annealing is based on the part function and ultimate part requirements.