Study On Preparation And Magnetization Behavior Of Nd(Y,La,Ce)-Fe-B High Abundant Rare Earth Permanent Magnet Alloys

Nd-Fe-B material,as a generation of"Magneto king",has become the key material of modern manufacturing industry.However,with the continuous development of Nd-Fe-B industry,some heavy rare earth elements（Pr,Nd,Dy,Tb）have become scarce,while La and Ce elements,which are abundant in the crust and have low cost,have not been fully utilized.Replacing part of Nd in Nd₂Fe₁₄B alloy with l REE can reduce the material cost of the alloy and obtain high magnetic properties.In this paper,the development and magnetization mechanism of rare earth permanent magnet with low unit magnetic energy cost and high performance and abundance are studied.In this paper,a series of nanocrystalline alloys were prepared by using Ce,Y,La rare earth elements instead of Nd element,and low melting point metal Ga instead of Fe element.Specific research results are as follows:1.The(Nd_0.8Y_0.2)_1-xFe₁₂Co₂B（x=0～0.4）nanocrystalline thin strip alloys were prepared by rapid quenching and amorphous crystallization methods.The effects of reduced Nd and Y rare earth elements on the microstructure and magnetic properties of the alloy samples were investigated.The results show that the grain size of Nd₂Fe₁₄B phase decreases from 43.4 nm to 25.0 nm andα-Fe phase decreases from34.3 nm to 29.1 nm with the decrease of rare earth elements from x=0 to x=0.2.The best magnetic properties of(Nd_0.8Y_0.2)_1-xFe₁₂Co₂B were obtained at x=0.2:H_cj=6.24k Oe,H_k/H_cj=0.38 and（BH）_max=9.5 MGOe.2.In this paper,(Nd_0.8La_0.2)_1-xFe₁₂Co₂B（x=0～0.5）nanocrystalline melt-spun alloy was prepared by the same melt-spun method and amorphous crystallization method.The effects of the reduction of Nd and Y rare earth elements content and certain crystallization process on the magnetic properties,magnetization behavior and microstructure of the alloy samples were investigated.The magnetic properties and hard magnetic Nd₂Fe₁₄B phase contents of Nd-Fe-B alloy can be improved by proper process,and the grain size can be reduced.The relative content of soft magnetic phaseα-Fe in the alloy is controlled effectively.The magnetization inversion characteristics of different alloy samples were analyzed by the relation curve between M_d（H）/M_r（∞）and M_r（H）/M_r（∞）.It is concluded that the coercivity mechanism of the alloy is nucleation mechanism.3.(Nd_0.7Ce_0.3)₂Fe₁₂Co_2-xGa_xB（x=0,0.2.0.4.0.6）and Ce₁₇Fe_78-xB₆Ga_x（x=0～3）nanocrystalline melt-spun alloys with different Ga contents were prepared by melt-spun method.The effect of Ga addition on magnetic properties,magnetization behavior and microstructure of alloy samples was studied.The content of hard magnetic phase,grain size can be improved by adding appropriate Ga element with low melting point.The magnetization inversion characteristics of different alloy samples were analyzed by recovery curve andδM curve,and the reason of enhancing the magnetic properties of Ce-Fe-B alloy with Ga was analyzed in combination with the microstructure.