材料期刊网

采用高真空电弧炉制备了Tb0.3Dy0.7Fe1.95-xZrx（x=0、0.03、0.06、0.09）合金,研究了不同Zr含量Tb0.3Dy0.7Fe1.95-xZrx（x=0、0.03、0.06、0.09）合金的晶体结构、微观组织及磁致伸缩性能。结果表明添加Zr后的Tb0.3Dy0.7Fe1.95-xZrx（x=0.03、0.06、0.09）合金基体相仍保持为MgCu2（C15型）立方Laves相结构,Zr添加后取代了Tb0.3Dy0.7Fe1.95合金中的稀土原子Tb、Dy而使晶格常数减小。添加Zr后,初生相ZrFe2的形成使得凝固液体富稀土从而抑制了RFe3有害相的生成,Zr在基体相RFe2中有限固溶而在富稀土相Re中不溶。初生相ZrFe2（C15型）可溶于与自身结构相同的RFe2（C15型）相中形成（Re、Zr）Fe2相。当Zr含量x=0.09时,Zr的溶解过饱和,从而在（Re、Zr）Fe2基体相上析出了富Zr相。Zr的添加量x对磁致伸缩的影响很大,少量Zr的添加对磁致伸缩的提高有利,但当含量x=0.09时,由于富Zr相,富Re相的析出对磁致伸缩的提高不利,但相对于Tb0.3Dy0.7Fe1.95母合金有少量提高。

The Tb0.3Dy0.7Fe1.95-xZrx（x=0,0.03,0.06,0.09） alloys were prepared by arc melting furnace.The crystal structure,microstructure and the magnetostriction of the Tb0.3Dy0.7Fe1.95-xZrx（x=0,0.03,0.06,0.09） alloys were studied.Results demonstrated that the matrix phase of the Tb0.3Dy0.7Fe1.95-xZrx（x=0.03,0.06,0.09） alloys consisted predominantly of the cubic Laves phase with MgCu2（C15-type） structure.After Zr addition,the lattice parameter of the Laves phase in the alloys decreased by substituting rare earth elements Tb and Dy.The formation of the ZrFe2 phase as the primary phase made the solidifying liquid become rich in rare earths and suppressed the formation of the deleterious RFe3 phase.Zr was found to be limited soluble in the matrix RFe2 phase and negligible soluble in Re-rich phase.ZrFe2（C15-type） phase could dissolve into the RFe2 phase which crystal structure is C15-type and form the matrix（Re,Zr）Fe2 phase.The solubility of Zr in the matrix phase was found to be supersaturated（x=0.09）,and Zr-rich phase formed as a new phase on the matrix（Re,Zr）Fe2 phase.The concentration of the element Zr affected the magnetostriction significantly.The improvement in magnetostriction was remarkably for the element Zr addition alloys with a low concentration as compared to the parent alloy Tb0.3Dy0.7Fe1.95.However,the decrease in magnetostriction at a higher concentration（x=0.09） was due to the formation of Zr-rich and Re-rich phases affecting magnetostriction.Whereas the magnetostriction had little improvement as compared to the parent alloy Tb0.3Dy0.7Fe1.95.