Open AccessMechanism of surface nanocrystallization in pure nickel induced by high-current pulsed electron beam
Author(s) -
Cheng Du-Qing,
Qingfeng Guan,
Zhu Jian,
Qiu Dong-Hua,
Xingwang Cheng,
Xuetao Wang
Publication year - 2009
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.58.7300
Subject(s) - materials science , dislocation , transmission electron microscopy , microstructure , crystallite , surface layer , scanning electron microscope , grain size , irradiation , nickel , layer (electronics) , composite material , cathode ray , severe plastic deformation , nanocrystal , deformation (meteorology) , electron , metallurgy , nanotechnology , physics , quantum mechanics , nuclear physics
High-current pulsed electron beam HCPEB technique was applied to irradiate the samples of polycrystalline pure nickel. Microstructures of the irradiated surface and sub-surface were investigated by using scanning electron microscopy SEM and transmission electron microscopy TEM. The experimental results show that the surface layer melted, and 2 μm depth remelted layer was formed on the top surface. Superfast solidification of melted layer results in the formation of nano-structure of 80 nm grain size in the remelted layer. In the sub-surface regions, the structures of dislocation walls and sub- dislocation walls in it with band shape were induced by severe plastic deformation, which become the dominant structures 5—15 μm below the irradiated surface. Those defect structures crossing with each other results in grain refinement, and nanocrystal grains about 10 nm in size were produced in the sub-surface layer.