Study On Fabrication High Si-content Fe-Si Alloy By Powder Metallurgy

Compared with traditional silicon steel, Fe-6.5wt%Si in theory is considered as an excellent property soft magnetism alloy. It has such excellent soft magnetism properties as higher permeability higher saturation magnetic induction near-zero magnetostriction and low core loss. Along with the increase of silicon content, the texture of silicon steel becomes brittle and mechanical properties are bed, it cannot been processed by conditional methods, so that the manufacture and the application of 6.5wt%Si steel were severely restricted. Spark plasma sintering (SPS) is a kind of new sintering technology for materials synthesis and processing, it has such advantages as high sintering speed, low sintering temperature, it also can retain the origin state of the sintered materials, as such make the sintered materials keep the state of un-equilibrium In this paper, SPS was conceived of treating iron covered silicon powder to keeping the origin state of the powder. Though rolling and heat-treating, the gained bulk became ribbon. The whole craftwork can be improved according the testing of magnetic properties.The iron covered silicon powder was fabricated separately by the milling method and the mixing method. Treated separately at 500℃, 600℃,700℃,800℃,900℃and 1000℃ for 1 minute, the iron silicon alloy bulk was attained. It also found that the density of the bulk was enhanced by the boost of the treated temperature. It was proved that the original state of the powder was kept.The iron silicon ribbon was attained through rolling. The push down scale were wildly using, the best one was 0.25mm and it also found that the density of the sample all boost. The sample which treated at 700℃ can attain the best out looking through rolling among the mixed ones. For the milled samples, the ones which treated at 900℃ and1000℃ all can attain intact out looking.The sample was treated at 1200℃ for 5 hours after treating at 1000℃ for 3 hours in the atmosphere of 94.4%Ar+5.6%H2.The silicon in the sample was also diffused into iron crystal. It also found that the density of the ultimate sample was affect by the original treated sample, high of the original treated sample, high of the ultimate sample.The magnetic properties result of the sample state that the ultimate 800℃-treated mixed sample has the coercive of 4.01Oe and the core loss at W10/50 of 3.28W/kg.The main reason may be there was large of oxide in the sample and the density was not high.