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利用强流脉冲电子束(HCPEB)技术对多晶纯镍进行了表面处理,并采用扫描电镜和透射电镜对强流脉冲电子束诱发的表面及亚表面的微观组织结构进行了分析.实验结果表明,HCPEB辐照后表面熔化,形成了深度约为2μm的重熔层,快速的凝固使重熔层中形成晶粒尺寸约为80nm的纳米结构.位于轰击表面下方5—15μm深度范围内强烈塑性变形引起的位错墙和其内部的亚位错墙结构是该区域的主要结构特征.这些缺陷结构通过互相交割细化晶粒,最终导致尺寸约为10nm的纳米晶粒的形成.
The polycrystalline pure nickel was surface-treated by HCPEB technique and the microstructure of the surface and subsurface induced by high-current pulsed electron beam was analyzed by scanning electron microscopy and transmission electron microscopy.The experimental results showed that , The surface of HCPEB after irradiation was melted to form a remelted layer with a depth of about 2μm and the rapid solidification resulted in the formation of nanostructures with a grain size of about 80nm in the remelted layer and strong plasticity in the depth range of 5-15μm below the bombarded surface Deformation caused by the dislocation wall and its internal structure of the sub-dislocation wall is the main structural features of the region.These defects by cross-grain refinement of each other, eventually resulting in the formation of nanocrystal size of about 10nm.