【作者】 王国栋；

【导师】 卫英慧；

【作者基本信息】 太原理工大学 ， 材料学， 2006， 硕士

【摘要】 在本文中，针对溶质在纳米晶中的扩散问题，选择纯铜作基体，利用表面机械研磨处理的方法，在其表面得到一定厚度的纳米晶层。然后进行表面离子注入碳，表面涂覆银浆和电镀镍等处理，在纳米晶层内部或表面得到一定浓度的间隙或置换溶质原子，热处理后考察它们的扩散行为。通过X-射线衍射、SEM、TEM、HRTEM和AES等一系列的表征手段，研究了纳米晶层结构中溶质扩散后显微组织和浓度梯度变化，得到如下结论： (1)纳米晶材料中，晶界占大量的分数，且空位浓度增加，离子注入过程中，碳原子可沿这些通道方便地迁移和聚集，从而提高了注入碳的浓度和深度。 (2)铜基体上离子注入碳，并经过适当的热处理后，会在其表面析出无定形碳和碳纳米洋葱，这是由电子束的照射作用引发的。碳原子快速扩散可能与纳米晶结构和离子辐照产生的损伤带来的缺陷(空位)有关。 (3)铜表面纳米化后其晶粒稳定性可以保持到300℃，晶粒长大的趋势不是很明显。在纳米晶铜表面涂覆Ag浆和电镀Ni后，在较低温度更多还原

【Abstract】 In this paper, nanocrystalline layer is obtained by SMAT on the surface of pure copper in order to investigate diffusion behavior of solute in it. By carbon ion implantation, painting Ag slurry and electric plating Ni into/on the surface of nanocrystalline copper, some stable diffusion sources are obtained, in which the atoms are interstitial or substitutional. The specimens treated are annealed at given temperatures for some time to study microstructures and concentration profiles of the solute by means of XRD, SEM, TEM, HRTEM and AES. The conclusions can be drawn as follows:(1) In the nanocrystalline materials, concentration and depth of carbon ion implantation are enhanced due to large amount of grain boundaries and vacancies contained, which carbon atoms will easily migrate and segregate along.(2) Amorphous carbon and carbon nano-onions are synthesized by carbon ion implantation into copper substrate heated at given temperatures, which is the result of electron beam irradiation. The fast diffusion possibly relates to the nanocrystalline structures and the irradiation induced injury by ion beams.(3) The nanosized grains still exist without obvious coarsening at 300°C. Diffusion phenomena on interface between Silver/Nickel layers, which are painted or electroplated on the surface of nanocrystalline copper respectively, and copper substrate is observed after annealed at lower temperatures. It更多还原