【摘要】 利用HRTEM和TEM研究了Al -Zn -Mg合金高能喷丸表面纳米化过程中微观结构的演变。结果表明,经表面高能喷丸处理,样品表面形成了厚度约2 0 μm的纳米晶层,随温度的增加,平均晶粒尺寸由约2 0nm逐渐增加到约1 0 0nm ;随着塑性变形量的增加,η′相在纳米晶区内几乎完全返溶,形成晶粒尺寸小于1 0 0nm的单相α过饱和固溶体。其原因可能是由于α固溶体的晶粒尺寸超细化而导致固溶度增加。更多还原

【Abstract】 The microstructural evolution of Al-Zn-Mg alloy during the high energy shot peening (HESP) process has been studied by means of high-resolution electron microscope (HREM) and transmission electron microscope (TEM). Experimental results show that nanocrystallized surface layer with thickness of about 20μm is formed after HESP, and the average grain size increases from about 20nm in the surface layer to about 100nm at a depth of 20μm. With increasing strain, η′precipitates in the nanocrystallized layer are almost completely dissolved, and nearly single phase α supersaturated solid solution with a fine grain size smaller than 100nm is obtained. The reason may be that grain size of α solid solution is fined, leading to the increase of solubility.更多还原