Morphology evolution and crystallographic feature of Nb nanowire in an in-situ NiTi-Nb nanocomposite
来源期刊：Rare Metals2014年第5期
论文作者：Zhen-Yang Liu Fang-Min Guo Zhong-Qiang Wang Li-Shan Cui
文章页码：563 - 567
摘 要：In–situ NiTi shape memory alloy–Nb nanowire nanocomposite was revealed to exhibit exceptional mechanical properties. The properties of high strength and ultra-large elastic strains are closely related with the high performance of in situ-formed Nb nanowire reinforcements. In this study, the morphology evolution and crystallographic feature of Nb nanowires in NiTi shape memory alloy matrix during cold drawing were investigated by means of transmission electron microscopy（TEM）. It is revealed that, as a result of the severe work hardening and amorphization of NiTi matrix, the cold work reduction of nanowire reinforcements can exceed that of the entire composite. The irregular-shaped Nb nanowires are reshaped to straight and smooth nanowires during cold drawing process. By means of TEM nanobeam diffraction,it is revealed that the in situ-formed Nb nanowire in such top-down processed NiTi–Nb composite keeps single crystalline over 1,000 nm at length direction. As a consequence, the aspect ratio of nanowire reinforcements in NiTi matrix exceeds 25:1.
Zhen-Yang Liu，Fang-Min Guo，Zhong-Qiang Wang，Li-Shan Cui
Department of Materials Science and Engineering, China University of Petroleum
摘 要：In–situ NiTi shape memory alloy–Nb nanowire nanocomposite was revealed to exhibit exceptional mechanical properties. The properties of high strength and ultra-large elastic strains are closely related with the high performance of in situ-formed Nb nanowire reinforcements. In this study, the morphology evolution and crystallographic feature of Nb nanowires in NiTi shape memory alloy matrix during cold drawing were investigated by means of transmission electron microscopy（TEM）. It is revealed that, as a result of the severe work hardening and amorphization of NiTi matrix, the cold work reduction of nanowire reinforcements can exceed that of the entire composite. The irregular-shaped Nb nanowires are reshaped to straight and smooth nanowires during cold drawing process. By means of TEM nanobeam diffraction,it is revealed that the in situ-formed Nb nanowire in such top-down processed NiTi–Nb composite keeps single crystalline over 1,000 nm at length direction. As a consequence, the aspect ratio of nanowire reinforcements in NiTi matrix exceeds 25:1.
关键词：
