直流和直流脉冲电解制备表面多孔结构对比研究

Comparative Study on Porous Surface Created by DC and DC pulse Electrochemical Machining

采用直流和脉冲电源电解加工不锈钢多孔表面,研究两种极化条件下的材料溶解过程及表面孔洞生长规律。结果发现:直流电解加工的材料溶解主要受浓差极化的控制,而脉冲电解加工的材料溶解主要受电化学极化的控制;直流电解加工孔洞的生长速度更快、表面腐蚀率更高,但孔洞数量少且均匀性差;而脉冲电源能增强电化学极化、抑制浓差极化,使孔洞的成核速度大于其生长速度,所以孔洞数量更多、均匀性更好,但加工效率比直流略低。

Porous surfaces were prepared by DC and DC pulse electrochemical machining on the surface of stainless steel,and material dissolution and holes growth characteristics were investigated. The results show that material dissolution is mainly controlled by the concentration polarization with the DC power supply,while it is under control of electrochemical polarization by DC pulse electrochemical machining. DC electrochemical machining makes the holes grow faster and the surface corrosion rate is higher,but the surface has small number holes and is poor uniformity. The pulse power supply can enhance the electrochemical polarization and reduce the concentration polarization ,which can promote pores formation and combat their growth. Therefore the holes number is larger and more homogeneous, but the processing efficiency is slightly lower.