Dynamic crystallization was introduced to improve the magnetic properties of NdFeB nanocrystalline permanent magnets by optimizing microstructure.The microstructure was studied by X-ray diffraction(XRD)and transmissio...Dynamic crystallization was introduced to improve the magnetic properties of NdFeB nanocrystalline permanent magnets by optimizing microstructure.The microstructure was studied by X-ray diffraction(XRD)and transmission electron microscopy(TEM).It has been determined that,compared with the conventional heat treatment,dynamic crystallization can shorten the crystallization time.Moreover,dynamic crystallization can refine grains,enhance the exchange-coupled interaction among grains,and promote the magnetic properties.As a result,the optimal magnetic properties of Nd_(10.5)(FeCoZr)_(83.4)B_(6.1)(B_(r)=0.685 T,H_(ci)=732 kA·m^(-1),H_(cb)=429 kA·m^(-1),(BH)_(m)=75 kJ·m^(-3))are obtained after dynamic crystallization heat treatment at 700℃for 10 min.展开更多
基金This work was financially supported by New Century Excellent Person Support Program of China(No.NCET-04-0873)Science Found for Distinguished Young Scholars of Sichuan Province(No.03ZQ026-006)Major Science Plan of Sichuan Province(No.03GG009-006).
文摘Dynamic crystallization was introduced to improve the magnetic properties of NdFeB nanocrystalline permanent magnets by optimizing microstructure.The microstructure was studied by X-ray diffraction(XRD)and transmission electron microscopy(TEM).It has been determined that,compared with the conventional heat treatment,dynamic crystallization can shorten the crystallization time.Moreover,dynamic crystallization can refine grains,enhance the exchange-coupled interaction among grains,and promote the magnetic properties.As a result,the optimal magnetic properties of Nd_(10.5)(FeCoZr)_(83.4)B_(6.1)(B_(r)=0.685 T,H_(ci)=732 kA·m^(-1),H_(cb)=429 kA·m^(-1),(BH)_(m)=75 kJ·m^(-3))are obtained after dynamic crystallization heat treatment at 700℃for 10 min.