| The isotropic magnetic powder MQP-16 is disposed by coupling agent KH-550 then made it into high performance magnets using epoxyp-henolic resin as binder. The hardness, density and magnetic performance of the magnets are tested. Various factors including viscosity and curing temperature of the binder, magnetic powder's oxidation behavior and the curing behavior of mixture were analyzed.The relation between magnetic performance and the particle size distribution is studied. The epoxy-Phenolic resin is synthesized using the KY-2055 and epoxy resin, after that magnets are prepared by powder and epoxy-phenolic resin.Compared with the epoxide magnets, the Br, Hciand (BH)max of the epoxide-phenolic magnets are higher.In these experiments epoxide-phenolic resin is used as binder, the effect factors of specimen forming such as pressure, holding time,curing temprature, curing time are investigated. The best process factors are obtained through experiments:molding temperature at 130℃,molding pressure under 1200MPa,holding time for 120s,curing time about 120min.As it is known that heat is the important factor which affects the epoxy-phenolic's viscosity. The time of the binder keeps the state of low viscosity at 130℃and the temperature-viscosity relationships are tested. The results are verified and supported by the time-viscosity theoretical formula.The oxidize type of powder and the curing kinetic of mixture made by powder and binder were analyzed through TG and DTA.It is concluded that phases of magnets are the same to those of powder through the XRD test, but the interplanar crystal spacing became longer, in the end of the paper the reasons also are studied. |
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