Effects Of Element Co-Addition On The Microstructure And The Magnetic Properties Of (Nd, Dy)₂(Fe, Cu, Co, Nb)₁₄B/α-Fe Magnets

(Nd_10.76Dy₁)(Fe_73.56-xCu_0.8Co₈Nb_x)B_5.88/α-Fe(x=0, 0.5, 1.0, 1.5)double phase nano-composite exchange-coupling hard magnet is a new candidate for permanent magnetic material. It is composed of the hard magnetic phase (Nd,Dy)₂(Fe,Cu,Co,Nb)₁₄B and the soft magnetic phase a-Fe in their nano scale to make the nano-composite exchange-coupling effect comes to work. In this paper, the preparation of (Nd,Dy)₂(Fe,Cu,Co,Nb)₁₄B/a-Fe is systematically studied. The influence of Nb to the crystallization process and its magnetic properties are discussed.During the preparation of the master alloy, the current and melting time are studied. According to the SEM and XRD test of the alloy with different compositions, the stable parameters for master alloy melting are given.According to the XRD analysis it is found all the four kind of alloys have excellent amorphous forming ability. It is also found that with the increase of the content of Nb, the temperature of (Nd_10.76Dy₁)(Fe_73.56-xCu_0.8Co₈Nb_x)B_5.88 (x=0, 0.5, 1.0, 1.5) for crystallization is increased.(Nd_10.76Dy₁)(Fe_72.56-xCu_0.8Co₈Nb_1.0)B_5.88/α-Fe has the best comprehensive magnetic properties with Hci=6656.3Oe, Mr =62.559emu/g and Ms=103.07emu/g.