中文摘要：

利用无氰镀银工艺制备具有纳米尺寸晶粒结构的银层,其纳米级的结构为其材料的研究与应用带来了理想的模型.在不同温度、不同电流密度条件下制备了系列纯镀银样品,并利用扫描电镜和X射线衍射研究镀层的微观表面形貌和结晶状态.结果表明,制备的银镀层具有纳米级的晶粒尺寸,理想条件下,其粒径集中在15~30 nm,晶粒择优取向沿（220）晶面.经70℃热水处理后,粒径增大至50~60nm,晶粒数减少近50%,故通过调整电镀条件和后处理,有望得到具有可控纳米尺寸晶粒结构的镀层.

英文摘要：

Cyanide-free silver plating was adopted to prepare silver layer with nano-sized grain structure, which is as an ideal model for the study in the materials science. Different plating conditions including the temperatures and the current density were investigated. Scanning electron microscopy and X-ray diffraction were used to study the microscopic surface morphology and crystalline state of silver layer. The result shows that the prepared silver layer has nano-sized grain structure. Under ideal conditions, the silver grains were oriented along the （220） plane, with the diameters mainly distributing between 15--30 nm. After 70 ℃ hot water treatment, the diameters grow to 50 60 nm, and the number of grain decreased by nearly 50 percent. So the cladding material of controllable size in the nano-sized grain structure may be obtained through adjusting plating conditions and after-treatment.