【摘要】 采用高能喷丸技术在 14 2 0铝合金上制备出纳米晶结构表层 ,利用X射线衍射仪、透射电子显微镜及高分辨电子显微镜研究由表层沿厚度方向的结构变化特征 ,并对硬度沿厚度方向的变化进行分析。结果表明 :经过表面高能喷丸处理 ,样品表面形成了厚度约为 2 0 μm的纳米晶层 ,平均晶粒尺寸由约 2 0nm逐渐增加到约 10 0nm ;距表层约 2 0～ 5 0 μm为亚微细晶层 ;表面纳米化的程度与塑性变形量有关 ;表面纳米化是通过位错滑移的塑性变形方式实现的 ;与样品的内部相比 ,表面硬度显著提高更多还原

【Abstract】 A nanostructured surface layer was fabricated on an aluminum alloy 1420 by using a high-energy shot peening (HESP) technique. HESP induced structure alone the depth of the treated sample surface layer was characterized by means of X-ray diffraction, transmission electron microscope and high-resolution electron microscope; and the hardness variation along the depth of the treated sample was examined. Experimental results show that nanostructured surface layer of about 20 μm of thickness is formed after HESP, the average grain size increases from (about)20 nm in the surface layer to about 100 nm at a depth of 20 μm. In the region of 2050 μm deep from the surface, there exists submicro-fine grained layer. The degree of the surface crystallization is related to the amount of the plasticity deformation.The surface nanocrystallization can realize by the method of the plastic deformation of dislocation slipping. The hardness of nanostructured surface layer is enhanced significantly after HESP compared with that of the initial sample.更多还原