Study On Preparation And Property Of Fesial Magnetic Powder Cores

Soft magnetic composite materials are produced by powder metallurgy process, their special properties are can't be compared by other materials. In the 21th century, soft magnetic composite materials have recently regained interest as magnetic cores for electrical converts. FeSiAl magnetic powder core is widely used in high frequency because of its high resistance, low magnetic core loss, and low price.In this paper, we have investigated the effect of the technologic procedure parameters on magnetic and mechanical properties of FeSiAl magnetic powder cores.Concerning the most important insulation procedure, first of all, the kinds of insulation solvnt was chosen without insulation so as to investigate the influence of bond solvent. Secondly, based on the first insulation scheme, adding some mica, the influence of component of bond solvent was studied; the last but not the least, making sure the mica is main insulation, the addition of mica was investigated to obtain the proper addition.The results showed that:high magnetic permeability, low core loss of samples were got when increasing bond proportion and mica in a certainty range; when mica content is 1.0%, resin content is 3.5%, the magnetic propertity is best;Compaction pressure is the basement to receive high magnetic property and good strength, adding pressure is better for permeability and strength; but much too big pressure will bring bad effect, so it's important to consider the ability of insultant to make sure proper pressure; the best compaction pressure is 18 t/cm2;Annealing treatment is also an important technology, through annealing, magnetic powder core can get high magnetic permeability, and low core loss. It's necessary to improve the annealing temperature when the resin is not burn down. Addition, it's also important to control annealing time to make sure the strain in the magnetic powder has fully released; the best annealing treatment process is 660℃×1h;Magnetic property of magnetic powder cores made with different size of powder are different. Magnetic permeability of magnetic powder core with big size powder is high, but its eddy loss is also very high. To receive good property, the size of the powder must be controlled, and proper addition is good to get down the eddy current loss so as to improve its property under high frequency; the best size compound is 4% of -100～+150,8% of -150～+250,34% of -250～+320,54% of -320;Optimum process:insultant with 1.0% mica, bond with 3.5% resin, compaction pressure is 18t/cm2, annealing at 660℃for 1h, size compound is 4% of -100～+150,8% of -150～+250,34% of -250～+320,54% of -320; magnetic property:permeability is 127.94, magnetic core loss is 12.439w/kg; strength is 28.5MPa.