Abstract
In traditional Nd-Fe-B-based sintered magnets,the composition,role of each element and microstruc-tures have been extensively investigated globally since they were invented in 1983.However,the effects of boron(B)content and post-sinter annealing(PSA)on the microstructure and magnetic properties have been least studied so far and the relative mechanisms are not yet clear.In this paper,we investigated the influence of B on the magnetic performance and microstructure of Nd-Fe-B sintered magnets origi-nally containing copper(Cu),gallium(Ga)and titanium(Ti).It is shown that the intrinsic coercivity has a substantial increment of 2.86 kOe and the remanence has a slight reduction of 0.16 kGs when B content is reduced from 0.980 wt.%to 0.900 wt.%.Moreover,there is a coercivity increment of 273%and 653%for samples with 0.980 wt.%and 0.900 wt.%B content after PSA,respectively.It is shown that the im-pacts of B content and PSA are significant and their regulation mechanisms are worthwhile to be studied systematically.Furthermore,it is revealed by microstructural analysis that high coercivity of the sample with 0.900 wt.%B after PSA results from the uniform distribution of Ga,Cu,Nd,and the formation of RE6(Fe,M)14(RE=Pr,Nd,M=Cu,Ga)compound in triple junction phases.The dilution of Fe content in grain boundary phases(GB phases)also plays an important role.It is found out that decrease of the re-manence is mainly due to reduction of the matrix phase and c-axis alignment degree.In this study,we explored a new path to develop Nd-Fe-B-based sintered magnets with high comprehensive properties by novel approaches through varying B content,PSA technique and co-adding trace elements.
基金项目
国家自然科学基金(52371188)
国家自然科学基金(52061015)
Young Talents Program of Jiangxi Provincial Major Discipline Academic and Technical Leaders Training Program(20212BCJ23008)
Jiangxi Province Double Thousand Plan(jxsq2023201085)
江西省自然科学基金(20212BAB214018)
Program of Qingjiang Excellent Young Talents of Jiangxi University of Science and Technology(JXUSTQJYX2020003)
国家级大学生创新创业训练计划(202110407013)
Technology Program of Fujian Province(2020H6027)
Technology Program of Fujian Province(2021T3063)
Selfdeployed Projects of Ganjiang Innovation Academy,Chinese Academy of Sciences(E055B002)
中国科学院重点研究项目(ZDRW-CN-2021-3)