脉冲电流密度对镍锰复合镀层结构及性能的影响

摘要

为获得高耐腐蚀性的镍锰二元合金复合镀层,采用脉冲电沉积方法在Q235碳钢基体上制备出平整、致密的镍锰复合镀层.研究了脉冲电流密度对镍锰镀层的微观结构、耐腐蚀性的影响.结果表明:随着脉冲电流密度变大镀层变的越来越平整、致密,当脉冲电流密度超过3.75 A/dm2时,晶粒尺寸变大且呈现不规则排列现象,在3.5%的NaCl溶液中耐蚀性下降.当脉冲电流密度为3.75 A/dm2时金属镀层最平整、致密,耐腐蚀性最好.%To obtain the composite coating of high corrosion resistance nickel and manganese alloy,a flat and compact nickel manganese composite coating was prepared on Q235 steel matrix with pulse electro deposition. The influence of pulse current density on microstructure and corrosion resistance of nickel and manganese coating was studied. The results show that the plating with larger pulse current density becomes more and more smooth,dense. When the pulse current density is more than 3. 75 A/dm2 ,grains will be in larger sizes. It presents the phenomenon of irregular arrangement. The corrosion resistance decreases as din 3. 5% NaCl solution. When the pulse current density is 3. 75 A/dm2 ,the metal coating is the most compact. It has the best corrosion resistance.