Microstructure evolution and magnetic properties of the Nd_9Fe_(81–x)Ti_4C_2Nb_4B_x(x=11, 13, 15) bulk magnets prepared by copper mold suction casting  

作　　者：詹玉勇 潘晶 姜晓丽 刘新才 董友仁 肖晓燕 

机构地区：[1]Ningbo State key Laboratory Base of New Functional Materials and Preparation Science, Faculty of Materials Science & Chemical Engineering, Ningbo University

出　　处：《Journal of Rare Earths》2015年第10期1081-1086,共6页稀土学报（英文版）

基　　金：Project supported by National Natural Science Foundation of China(51174121);Zhejiang Province Science and Technology Innovation Team of Key Projects(2010R50016-30)

摘　　要：The bulk nanocomposite magnets of Nd9Fes1-xTi4C2Nb4Bx （x= 11, 13, 15） in sheet form with the thickness of 0.7 mm were prepared by copper mold suction casting and subsequently annealing. The microstructure evolution and magnetic properties of bulk magnets were studied. It was shown that the as-cast microstmcture ofbtflk alloys were composed ofNdEFe14B, a-Fe, FeaB crystalline phases and an amorphous matrix, and that the glass formability of alloy was improved with increasing the B content. The DSC analysis showed that the as-cast bulk alloys had the crystallization behavior of a two-step process. After annealing at the temperatures which was 40453 K higher than their onset temperatures of the second exothermic peak, Nd9Fe81 xTi4C2Nb4Bx （x=11, 13, 15） bulk alloys obtained a finely mixed structure which were composed of Nd2Fe14B, a-Fe, Fe3B, （Nb,Ti）C crystalline phases and a residual amorphous phase, whose magnetic properties were significantly enhanced. For the bulk magnets of Nd9Fes1-xTi4CENb4Bx （x=11, 13, 15）, the optimal magnetic properties of Br=0.63 T, iHc= 155.1 kA/m, （BH）max= 18.73 kJ/m3 could be achieved when x= 13 after annealing at 983 K for 10 min.The bulk nanocomposite magnets of Nd9Fes1-xTi4C2Nb4Bx （x= 11, 13, 15） in sheet form with the thickness of 0.7 mm were prepared by copper mold suction casting and subsequently annealing. The microstructure evolution and magnetic properties of bulk magnets were studied. It was shown that the as-cast microstmcture ofbtflk alloys were composed ofNdEFe14B, a-Fe, FeaB crystalline phases and an amorphous matrix, and that the glass formability of alloy was improved with increasing the B content. The DSC analysis showed that the as-cast bulk alloys had the crystallization behavior of a two-step process. After annealing at the temperatures which was 40453 K higher than their onset temperatures of the second exothermic peak, Nd9Fe81 xTi4C2Nb4Bx （x=11, 13, 15） bulk alloys obtained a finely mixed structure which were composed of Nd2Fe14B, a-Fe, Fe3B, （Nb,Ti）C crystalline phases and a residual amorphous phase, whose magnetic properties were significantly enhanced. For the bulk magnets of Nd9Fes1-xTi4CENb4Bx （x=11, 13, 15）, the optimal magnetic properties of Br=0.63 T, iHc= 155.1 kA/m, （BH）max= 18.73 kJ/m3 could be achieved when x= 13 after annealing at 983 K for 10 min.

关 键 词：copper mold suction casting nanocomposite bulk magnets microstructure annealing treatment magnetic properties rare earths 

分 类 号：TB33[一般工业技术—材料科学与工程] TG156.2[金属学及工艺—热处理]