速凝铸带厚度对烧结NdFeB强韧性和磁性能的影响  

Obvious Difference in Fracture Strength and Magnetic Properties by Strip Casting Thickness of NdFeB

作　　者：严密[1] 于濂清[1] 张文勇[1] 王伟[1] 

机构地区：[1]浙江大学硅材料国家重点实验室,浙江杭州310027

出　　处：《稀有金属材料与工程》2006年第7期1089-1091,共3页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(50471041);浙江省科技计划重点支持项目(2003C21021)

摘　　要：研究了烧结NdFeB磁体强韧性和磁性能对速凝铸带厚度的依赖性。结果表明:磁体的抗弯强度随着铸带厚度的减小而迅速增大,当铸带较薄时,带内的微细晶制粉时形成较多氧化的细小颗粒,它们能有效延缓烧结过程中的晶粒生长速度。由断裂强度公式得知,晶粒越小,磁体抗弯强度越高,因此用0.38mm厚铸带制成的磁体抗弯强度比0.45mm厚铸带制成的磁体大得多。同时,铸带厚度为0.45mm时,带内晶粒尺寸分布较好(3μm^5μm),此厚度铸带制备的磁体磁性能可获得最佳值。The dependence of fracture strength and magnetic properties of sintered NdFeB magnets on the thickness of strip casting is studied. It is found that the bending strength rapidly increases with the decrease of the thickness of strip casting. A lot of ultra fine grains would be easily oxidized during the jet milling for the thinner strip castings. The oxidization restrains the grain growth effectively, as a result, the grains in the sintered magnets by the thinner strip casting are fine. According to the formula of fracture strength for ceramic materials, the finer the grain, the higher the fracture strength of magnets. For example, the bending strength of the magnets produced by strip casting with a thickness of 0.38 mm is 50% larger than that of 0.45 mm. In addition, the strip casting of 0.45 mm in thickness has a more homogeneous distribution of grain size within a range of 3 μm-5 μm, near the optimal grain size distribution. So the sintered magnets made of the thinner strip castings possess better magnetic properties.

关 键 词：速凝铸带 钕铁硼 磁性能 断裂强度 

分 类 号：TM271[一般工业技术—材料科学与工程]