Research Of Smelting Technology For NdFeB Permanent Magnet Series Initial Alloy

NdFeB series alloy is one of importment permanent magnetic materials and was concerned widely.The future research direction concerned NdFeB series alloy includes three aspects that increasing magnets comprehensive performance,alloy composition diversity and advanced preparing process.In accordance with the current market situation and technical requirements of sintering NdFeB alloy,this research is focus on strip casting process of NdFeB series master alloys without Dy by the reasonable composition design and process improvement.The researchgoal is striving to guarantee on the basis of the magnetic properties,especially in the guarantee of magnet premise coercive force,and improving the comprehensive performance(mechanical properties,corrosion resistance,and thermal stability).In this paper,excellent comprehensive performance NdFeB composition of optimized design was determined by summarizing the existing research results,theoretical analyzing and experiment.Through comprehensive contrasting experiment,Ga,Cr,Dy,Co,Nb,Cu,Ni,B,Gd,Y,Zr,Pr and composite rare earth were added into the NdFeB magnet alloy and coercive force,mechanical properties,corrosive comprehensive properties and microstructure are studied,and finally,the designed composition(Nd,Pr)13Zr3Fe78B6 alloy was determined.Based on the designed composition(Nd,Pr)13Zr3Fe78B6 alloy,the problem of traditional mold casting process were found,then the basic parameters of strip casting process by effective experimental methods.Based on a reasonable casting model,the solidification process of(Nd,Pr)13Zr3Fe78B6 alloy was simulated by the calculation experiment.Finally,on the conditions of a temperature of 1673-1723K and a turning speed 1.5?2.0 m/s under low oxygen environment,the(Nd,Pr)13Zr3Fe78B6 alloy slice formed complete columnar crystal,rich rare earth phase in the lord around equably dispersed phase,without alpha Fe phase can be obtained.The thickness of(Nd,Pr)13Zr3Fe78B6 alloy was distributed in the 0.2?0.45 mm range.Through the analysis of demagnetization curve,the(Nd,Pr)-Fe-B products with ideal properties can be acquired.