拉伸变形对电沉积镍镀层微观结构及力学性能的影响

Effect of Tensile Deformation on the Microstructare and Mechanic Properties of Electrodeposited Nickel Coating

采用电沉积法在低碳钢基体上制备了韧性较好的镍镀层,并对镀镍钢带进行了拉伸试验。通过扫描电镜(SEM)和X射线衍射(XRD)分别对镍镀层变形前后的表面形貌和织构进行了研究。用纳米压痕的方法对拉伸变形前后的镍镀层样品进行了载荷-深度曲线的测试,并测量了电沉积镍镀层变形前后的硬度与杨氏模量。结果表明,拉伸变形后的镍镀层表面粗糙度变大,出现起皱,但并没有产生新的织构,只是原有织构的强度发生了变化,其硬度和杨氏模量都明显减小。对于同一样品,加不同载荷会导致不同的压痕深度,随深度的增加,测得的压痕硬度和样式模量也有明显降低。

Nickel coating with good toughness was electrodeposited on low carbon steel substrate,and the Ni-coated steel strips were used for tensile test.The morphologies and textures of the Ni coatings before and after tensile deformation were analyzed by means of scanning electron microscopy and X-ray diffraction.The load-indentation depth curves of the Ni coatings before and after tensile deformation were measured using nano-indentation method,while the hardness and Young' s modulus of the Ni coatings were also measured.It was found that the surface roughness of the electrodeposited Ni coating increased after tensile deformation,accompanied by the appearance of wrinkling.No new textures were formed in the Ni coating after tensile deformation,though the strength of the original texture was varied,leading to noticeable decrease in both the hardness and Young' s modulus of the Ni coating.Moreover,the indentation depth of the same coating sample varied with indentation load,and the indentation hardness and Young' s modulus of the Ni coatings obviously decreased with the increasing indentation depth.