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通过直流电沉积技术制备具有高密度纳米孪晶结构的Ni,并对该材料中存在的五次孪晶结构进行了深入系统的电子显微分析.获得了纳米孪晶Ni中五次孪晶结构的HRTEM图像和SAED花样;研究了单个晶粒内部五次孪晶的结构特性、分布规律.结果表明,五次孪晶是由5个{111}晶体旋转组成,五次旋转孪晶产生的7.35°本征间隙至少由五次孪晶中的2个孪晶界分担;而且分担间隙的孪晶界呈现宽化现象,并且分解为新的孪晶,导致五次孪晶晶粒在整体形状上不具有五次对称性,呈现出一定的不规则形状.TEM截面形貌分析表明,电沉积纳米孪晶Ni呈现{110}面平行样品表面织构,晶粒为柱状晶分布,柱状生长方向为[110].通过综合结构表征,给出了五次孪晶在三维空间的结构模型.
Ni with high-density nano-twin structure was prepared by direct current deposition technique, and five-twins structure existed in the material was systematically investigated by electron microscopy. The five-twins structure of nano-twin was obtained HRTEM image and SAED pattern.The structural characteristics and distribution of five twins in a single grain were studied.The results show that the fifth twins are composed of five {111} crystal rotations, and the fifth twins produce 7.35 ° The intrinsic interspaces are shared by at least two twin boundaries in the five twins; and the twin boundaries sharing the gap exhibit a widening phenomenon and are resolved into new twins, resulting in the five-fold twin grains not being globally shaped With five symmetry, showing a certain irregular shape.TEM cross-sectional morphology analysis showed that the electrodeposited nano-twins Ni presented {110} plane parallel to the sample surface texture, grain size distribution of columnar crystals, columnar growth direction [ 110] .The structural model of five twins in three-dimensional space is given through comprehensive structural characterization.