钴含量对电沉积纳米晶镍钴合金组织与力学性能的影响  

Effect of Co content on structures and mechanical properties of electrodeposited nanocrystalline Ni-Co alloys

作　　者：许伟长[1] 戴品强[1,2] 郑耀东[1] 

机构地区：[1]福州大学材料科学与工程学院,福州350108 [2]福建工程学院材料科学与工程系,福州350108

出　　处：《中国有色金属学报》2010年第1期92-99,共8页The Chinese Journal of Nonferrous Metals

基　　金：福建省自然科学基金资助项目(E0810006);福州大学创新计划资助项目

摘　　要：采用脉冲电沉积技术制备钴含量在2.4%～59.3%范围内的镍钴合金。利用XRD与TEM技术对纳米晶镍钴合金的组织结构进行表征。结果表明:所有成分的纳米晶镍钴合金均为面心立方结构的单相固溶体,平均晶粒尺寸为11～24nm,且平均晶粒尺寸随钴含量的增加而减小,镍钴合金镀态下TEM组织中观察到的晶粒尺寸与XRD测量结果一致;纳米晶镍钴合金抗拉强度为1300～1650MPa,断裂伸长率为10.5%～14.5%,镍钴合金的抗拉强度与断裂伸长率均随钴含量的增加而提高;随着钴含量的不断增加,镍钴合金在单向拉伸过程中的应力诱发晶粒长大被逐渐抑制,提高加工硬化率,塑性失稳被延迟,从而提高塑性。Ni-Co alloys with Co content varying from 2.4% to 59.3% were prepared by pulse electrodeposition nanocrystalline. The microstructures of the nanocrystalline Ni-Co alloys were characterized by XRD and TEM. The analysis of XRD indicates that nanocrystalline Ni-Co alloys are all face-centered cubic structure, single-phase solid solution with an average grain size in the range of 11-24 nm, and the average grain size decreases with increasing Co content. The grain size observed in the TEM structures of as-deposited Ni-Co alloys is consistent with that measured by XRD. For nanoerystalline Ni-Co alloys, the ultimate tension strength is in the range of 1 300-1 650 MPa and the elongation to failure is in the range of 10.5%-14.5%. Both the ultimate tension strength and the elongation to failure increase with increasing Co content. With increasing Co content, the grain growth in the process of tension deformation is gradually suppressed leading to improved work hardening rate and delayed plasticity instability, which aids to obtain enhanced ductility.

关 键 词：镍钴合金 纳米晶 力学性能 晶粒长大 变形机制 

分 类 号：TG174.441[金属学及工艺—金属表面处理]