【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。更多还原

【Abstract】 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 nanocrystalline 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.更多还原