烧结Nd_(25.5)Dy_(6.5)Co_(13)Fe_(bal)M_(1.05)B_(0.98)磁体温度稳定性和力学性能研究  

Study on temperature stability and mechanical properties of sintered Nd_(25.5)Dy_(6.5)Co_(13)Fe_(bal)M_(1.05)B_(0.98)magnet

作　　者：徐吉元 张家滕 孟睿阳 陈红升[1] 方以坤[1] 董生智[1] 李卫[1] Xu Ji-Yuan;Zhang Jia-Teng;Meng Rui-Yang;Chen Hong-Sheng;Fang Yi-Kun;Dong Sheng-Zhi;Li Wei(Division of Functional Materials,Central Iron&Steel Research Institute,Beijing 100081,China)

机构地区：[1]钢铁研究总院有限公司,功能材料研究院,北京100081

出　　处：《物理学报》2023年第7期368-375,共8页Acta Physica Sinica

基　　金：国家重点研发计划(批准号:2021YFB3502900)资助的课题.

摘　　要：本文采用速凝甩带-氢破-气流磨-取向成型-烧结回火等工序,同时添加Dy和Co元素,制备了烧结Nd_(25.5)Dy_(6.5)Co_(13)Fe_(bal)M_(1.05)B_(0.98)磁体(Co13磁体),室温下磁能积(BH)_(max)=30.88 MGOe,矫顽力H_(cj)=19.01 kOe.与Nd_(30)Dy_(1.5)Co_(0.5)Fe_(bal)M_(1.05)B_(0.98)(35SH)磁体相比,Co13磁体的室温磁性能略低,但温度稳定性显著提升,剩磁温度系数α从-0.136%/℃提升至-0.065%/℃(室温-180℃);居里温度T_(C)从310℃升高至约454℃;最高使用温度T_(W)从165℃提升到约200℃.力学性能测试和断口分析表明,Co13磁体中由于Co含量较高,主相晶粒发生解理断裂的比例提高,抗弯强度与35SH磁体相比,虽然有所降低,但是仍为2:17型Sm-Co磁体的近2倍.Co13磁体发生解理断裂的原因,可能是Co元素在2∶14∶1主相中择优取代Fe,导致晶格畸变,降低了主相晶粒强度.微观组织分析表明,Co13磁体晶界相中存在高Co区,其成分接近(Nd,Dy)(Fe,Co)_(3),这可能是导致矫顽力较低的原因之一.The sintered Nd_(25.5)Dy_(6.5)Co_(13)Fe_(bal)M_(1.05)B_(0.98) magnet(Co13 magnet)and Nd_(25.5)Dy_(6.5)Co_(13)Fe_(bal)M_(1.05)B_(0.98)magnet(35SH magnet)are prepared by strip casting,hydrogen decrepitation,jet milling,orienting compression,sintering and annealling.The maximum energy product(BH)_(max) and coercivity H_(cj) of Co13 magnet at room temperature are 30.88 MGOe and 19.01 kOe,which are lower than those of 35SH magnet.By adding Co and Dy,the remanence temperature coefficient a,curie temperature TC,and max operating temperature TW significantly increase form–0.136%/℃to–0.065%/℃(25–180℃),310℃to 454℃,and 160℃to 200℃respectively.Mechanical property test and fracture analysis show that owing to the high content of Co in the magnet,the proportion of cleavage fracture in the main phase grains increases,and the bending strength Rbb decreases compared with the Rbb of 35SH magnet,which is nearly twice that of 2∶17 type Sm-Co magnet.The reason for Rbb decreasing might be that Co element preferentially replaces Fe in the 2∶14∶1 main phase,which leads the lattice to be distorted and the grain strength of the main phase to decrease.The microstructure analysis shows that there exists a high Co region in the grain boundary phase of Co13 magnet,and its composition is close to(Nd,Dy)(Fe,Co)_(3),which might be one of the reasons for coercivity H_(cj) decreasing.

关 键 词：烧结ND-FE-B 温度稳定性 最高使用温度 力学性能 

分 类 号：TM273[一般工业技术—材料科学与工程]