【摘要】 钢件镀镍前的电化学抛光工艺对镀层性能有较大影响。以低碳钢Q235A为基材,研究电化学抛光工艺参数对镍镀层性能的影响规律,探讨了在低碳钢表面制备性能优良的镀镍层的较优工艺。首先选择4组、每组2件样品,研究电化学抛光中有、无磁性搅拌对镍镀层的影响。在此工作基础上,采用正交试验,选择16件样品研究磁性搅拌下抛光工艺参数对镀层的影响。用数显外径千分尺测试镀层厚度、表面轮廓测量仪2302A测量表面粗糙度值Ra、纳米压痕仪Nano Indenter XP测试镍镀层的弹性模量及硬度。结果显示:电化学抛光时加磁性搅拌可以使镀层表面光滑、镀层增厚;电化学抛光电流密度对镀层表面粗糙度影响较小,但对镀层厚度、弹性模量及硬度的影响很大;而电化学抛光温度、抛光时间对镀层表面粗糙度、镀层厚度的影响与抛光电流密度有关。在其他条件相同的情况下,选择抛光时间15 min、电流密度30 A/dm2,抛光温度为65℃时得到的镍镀层弹性模量、硬度可以达到最大值。更多还原

【Abstract】 The effect of electrochemical polishing with and without magnetic stirring on the elastic modulus and hardness of electroplated Ni coating on Q235 A low carbon steel was investigated while four groups of specimens(each group of specimens contained 2 pieces of specimens) were selected.The electrochemical polishing parameters in the presence of magnetic stirring were then optimized based on orthogonal tests of 16 pieces of specimens.The thickness of as- prepared Ni coating was measured with a thickness meter.The surface roughness of the Ni coating was measured with a surface profilometer.and its elastic modulus and hardness were determined with a nano-indenter.Results indicated that introducing magnetic stirring during the electrochemical polishing helped to obtain Ni coating with smooth surface and increased thickness.The current density of electrochemical polishing had little influence on the surface roughness of the Ni coating,but it had significant influence on the thickness,elastic modulus and hardness of the coating.Moreover,the influence of temperature and time of electrochemical polishing on the surface roughness and thickness of the Ni coating was related to the current density.Particularly,when the time,current density and temperature were selected as15 rain,30 A/dm~2 and 65℃,resultant Ni coating exhibited the maximum elastic modulus and hardness.更多还原