Of Smco Permanent Magnet Material Microstructure Analysis

Sm₂(Co,Cu,Fe,Zr)₁₇ permanent magnet materials which studied in the article, havingcharacteristics of high magnetic performance, low temperature coefficient andcorrosion-resistant, are applied most widely used among SmCo permanent magneticmaterials. Researches pay lots of attention on its high performance. The most works areput on process and element content to improve materials' performance. However assintered products, there are more factors which closely relate to performance, such asmicrostructure, heat treatment and chemical compositions."Investigation of the morphologic analyze on Sm₂(Co,Cu,Fe,Zr)₁₇ permanentmagnet materials" is brought out focusing on microstructure. The relation betweenmicrostructure and its performance is studied. Begin with investigating the oxidationbehavior of the magnets during process, the sintered samples were analyzed, the seriesmicrostructure researches of materials are performed.Sm₂(Co,Cu,Fe,Zr)₁₇ permanent magnet materials are product in commercialmethod powder metallurgy. During the processes, oxygen enters material inevitably,destroying capability. The previous analyses in microstructure of magnets were takenon their metallographical surface, while in this study was taken on the natural fractureby stroke. By three microstructure method SEM,EDS and XRF, combiningmacroscopical method particle granularity analyzer and oxygen and nitrogen analyzer,the Sm₂(Co,Cu,Fe,Zr)₁₇ cast, particle, sinters' microstructure and chemicalcompositions are analyzed. From the result, the oxidation hole of Sm₂O₃ particle is themain reason that destroy the performance, the oxygen is distributed inside 2mm fromthe surface of the material; there are two defects of the alloy which results from theinsymmetircal rate of cooling; the powder produced by air current milling procedures isbetter than that produced by machine milling, the shape of powder is close to globosity,the sintered material is in better performance. According the result, the rule that oxygenentering material, the process of oxidation Sm and the existence model of oxygen inmagnetic material are studied. The effect of the powder's feature on the magnetic properties also studied.Apply the conclusion on the commercial method powder metallurgy, the lowoxygen technics of rear earth permanent magnet are supported, which advanced theperformance and security.