Method for fabricating intricate parts with good soft magnetic properties

Abstract

In the present invention, nickel and phosphorous are simultaneously plated onto the surface of iron powder, mixed iron and nickel powder, or iron-nickel pre-alloyed powder, to form iron-nickel-phosphorous ternary alloy powders with very uniform distribution of phosphorous, with concentrations ranging between 2.0 and 6.0 wt%. When mixed with an appropriate amount of organic binder, these powders may be used as raw materials for injection molding. Intricate parts thus formed can be sintered at relatively low temperatures to attain high sintered density, large grain size, and isotropic shrinkage. The sintered microstructure thus obtained is characterized by spheroidal grains embedded in continuous intergranular insulating phosphide phase. The magnetic properties of the resulting material are substantially improved as compared to those of powder processed products. By controlling the fractions of phosphorous and nickel in the final ternary alloy, products that are intended for use in alternating magnetic fields with different frequencies can be produced.

Dependencies are inferred from the claim text.