Magnetic properties and microstructures of terbium coated and grain boundary diffusion treated sintered Nd-Fe-B magnets by magnetron sputtering
来源期刊：JOURNAL OF RARE EARTHS2021年第2期
论文作者：Wei Zhu Yang Luo Zilong Wang Xinyuan Bai Haijun Peng Dunbo Yu
文章页码：167 - 173
摘 要：Tb coating on the surface of commercial sintered Nd-Fe-B magnet was prepared by DC magnetron sputtering.The secondary heat treatment was used to regulate the microstructure for the enhancement of coercivity,namely diffusion treatment and annealing treatment.The coercivity increases significantly from 18.3 to 28.0 kOe,the remanence decreases slightly from 14.1 to 14.0 kGs,and the comprehensive magnetic properties are higher than 75(Hcj+（BH）max=76.7).SEM results indicate that,on the one hand,950℃ is the optimal diffusion temperature.Lower diffusion temperature results in insufficient diffusion of Tb element.Higher diffusion temperature can lead to the main phase grain growth,the decrease of Nd-rich phase,and forming holes in the magnet.On the other hand,500℃ is the optimal annealing temperature.Lower annealing temperature can result in the reduction of Nd-rich phase.Higher annealing temperature can generate the non-defined Nd-rich thin layer between grains.
Wei Zhu1,2,3，Yang Luo1,2,3，Zilong Wang1,2,3，Xinyuan Bai1,2,3，Haijun Peng1,2,3，Dunbo Yu1,2,3
1. National Engineering Research Center for Rare Earth Materials,GRINM Group Co.,Ltd.2. GRIREM Advanced Materials Co.,Ltd.3. General Research Institute for Nonferrous Metals
摘 要：Tb coating on the surface of commercial sintered Nd-Fe-B magnet was prepared by DC magnetron sputtering.The secondary heat treatment was used to regulate the microstructure for the enhancement of coercivity,namely diffusion treatment and annealing treatment.The coercivity increases significantly from 18.3 to 28.0 kOe,the remanence decreases slightly from 14.1 to 14.0 kGs,and the comprehensive magnetic properties are higher than 75(Hcj+（BH）max=76.7).SEM results indicate that,on the one hand,950℃ is the optimal diffusion temperature.Lower diffusion temperature results in insufficient diffusion of Tb element.Higher diffusion temperature can lead to the main phase grain growth,the decrease of Nd-rich phase,and forming holes in the magnet.On the other hand,500℃ is the optimal annealing temperature.Lower annealing temperature can result in the reduction of Nd-rich phase.Higher annealing temperature can generate the non-defined Nd-rich thin layer between grains.
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