球磨工艺和合金元素Al对机械合金化制备NbVMoTa高熵合金粉末的影响  

Effects of Ball Milling Process and Alloying Element Al on Preparation of NbVMoTa High Entropy Alloy Powders by Mechanical Alloying

作　　者：常杜娟 邓莉萍[1] 罗军明[1] CHANG Dujuan;DENG Liping;LUO Junming(School of Materials Science and Engineering,Nanchang Hangkong University,Nanchang 330063,China)

机构地区：[1]南昌航空大学材料科学与工程学院,南昌330063

出　　处：《材料导报》2023年第10期181-185,共5页Materials Reports

基　　金：国家自然科学基金(52161021);江西省教育厅科技计划项目(DA202101164);南昌航空大学博士启动基金(EA201901206)。

摘　　要：采用机械合金化制备NbVMoTa难熔高熵合金粉末,研究了球磨转速、球磨时间和合金元素Al对合金化过程中粉末相结构和形貌等的影响。采用X射线衍射仪(XRD)、附带能谱仪(EDS)的扫描电子显微镜(SEM)和透射电子显微镜(TEM)对粉末进行了分析。结果表明:随着球磨转速的提高,粉体颗粒间有效碰撞次数增加,相变能量增多,结晶速度加快,促进了Nb、V、Mo、Ta各元素粉末之间的固溶,转速由200 r/min提高至400 r/min后,不同粉末之间的固溶明显增强,在400 r/min条件下,随着球磨时间的延长,粉末间的固溶更加明显,球磨100 h,粉末之间实现合金化,形成具有单一BCC结构的细晶NbVMoTa难熔高熵合金粉末,粉末粒径在30~60 nm。添加的合金元素Al与其他元素之间形成较强的极性键,促进了系统的有序排列,混合焓为负值,可加快体系的合金化进度,(NbVMoTa)88 Al 12粉末在400 r/min下球磨60 h即可实现合金化,形成单一BCC结构的细晶难熔高熵合金粉末,粉末粒径在40~60 nm。NbVMoTa refractory high entropy alloy(RHEA)powders were prepared by mechanical alloying.The effects of milling speed,milling time and alloying element Al on phase structure and morphology during mechanical alloying process were investigated.The powders were characte-rized by X-ray diffraction(XRD),scanning electron microscope(SEM)equipped with energy dispersive spectroscopy(EDS)and transmission electron microscope(TEM).The results show that the intersolubility of Nb,V,Mo and Ta element powders increases obviously by the increase of effective collision number,phase transformation energy and crystallization speed when the milling speed increases from 200 r/min to 400 r/min.Furthermore,the intersolubility of various powders improves significantly with milling time at 400 r/min.Especially,the fine NbVMoTa RHEA powders with a particle size of about 30—60 nm form a single body-centered cubic(BCC)structure after milled at 400 r/min for 100 h.In addition,the alloying progress can be accelerated by adding alloying element Al due to the formation of strong polar bonds,the orderly arrangement and the negative mixing enthalpy between Al and other component elements.The fine(NbVMoTa)88 Al 12 RHEA powders with single BCC structure form after milled at 400 r/min for 60 h and the powders particle size is about 40—60 nm.

关 键 词：机械合金化 难熔高熵合金 BCC固溶体 铝 

分 类 号：TG146.4[一般工业技术—材料科学与工程]