摘要
涂敷法作为重稀土热扩渗技术的一种,具有低成本、操作简单等优点,现已成为工业化应用的主流技术。目前为了获得好的热扩渗效果,需要涂覆大量的DyF_(3)粉,这造成不必要的浪费。针对该问题,利用自主研发的DyF_(3)新型涂料烧结NdFeB进行热扩渗处理。研究了不同DyF_(3)涂敷量热扩渗磁体的性能、微观组织结构和Dy元素分布。结果表明,Dy浓度差是热扩渗的驱动力,因此涂敷量对样品矫顽力提升有重要影响。涂敷量较少时,Dy元素热扩渗不充分,导致矫顽力的提升有限;随着涂覆量增加,Dy元素的扩渗充分,在晶界中均匀分布,此时磁体具有最佳的综合磁性能;继续增加涂覆量,Dy和涂液中C、F等元素开始进入主相晶粒,造成磁性能的恶化,磁性能反而下降。因此重稀土涂覆量应在适当范围内,过多和过少都会造成热扩渗效果不好。最佳DyF_(3)涂敷量为0.81%(质量分数),经过热扩渗后,矫顽力由14.60kOe提升到19.78kOe,剩磁的下降很小,磁体达到最佳的综合性能。
As a promising heavy rare earth thermal diffusion technology,the coating method has the advantages of low cost and simple operation.It has become the mainstream technology for industrial application.In order to obtain a good thermal diffusion effect,a large amount of DyF_(3) powder should be coated on surface of the magnets,which causes unnecessary waste.The influence of different DyF_(3) coating amount on the performance of the sintered NdFeB magnets and Dy element distribution process were studied.A homemade special DyF_(3) coating was employed for thermal diffusion treatment.The results showed that Dy concentration was the driving force of the thermal diffusion,so the coating amount had an important influence on the enhancement of coercivity.When the coating amount was lower,the thermal diffusion of Dy element was not sufficient,resulting in the limited enhancement of coercivity.With the increase of coating amount,Dy element was fully diffused and evenly distributed in the grain boundary,which made the magnet had the best comprehensive magnetic properties.When continue to increase the amount of coating,Dy element begins to enter the main phase grains,causing the deterioration of the magnetic properties.Consequently,the amount of heavy rare earth coating should be within the appropriate range,too much or too little will not be conducive to the effect of thermal diffusion.The optimal coating amount of DyF_(3) was 0.81 wt.%.After thermal diffusion,the magnet achieved the best comprehensive performance,and the coercivity increased from 14.60 kOe to 19.78 kOe.
作者
向令
赵东
王琳
刘立民
江盼
裴文利
XIANG Ling;ZHAO Dong;WANG Lin;LIU Limin;JIANG Pan;PEI Wenli(College of Material Science and Technology,Northeastern of University,Shenyang 110819,Liaoning,China;Key Laboratory for Anisotropy and Texture of Materials Ministry of Education,Northeastern of University,Shenyang 110819,Liaoning,China;Aviation Foundation College of Naval-aviation University,Yantai 264001,Shandong,China)
出处
《金属功能材料》
CAS
2021年第5期35-42,共8页
Metallic Functional Materials
基金
国家自然科学基金资助项目(51871045,52071070)
中央高校基本科研业务资助项目(N2017003)。
关键词
NDFEB
渗镝
矫顽力
涂敷量
NdFeB
Dy-diffusion
coercivity
coating amount
