三价铬电沉积过程强化规律研究

The regularity and process enhancement for Cr(Ⅲ) electrodeposition

铬镀层具有优异的机械和抗腐蚀性能,传统六价铬电镀存在高毒、高污染等问题,三价铬绿色电镀工艺受到普遍关注,但铬镀层不能持续增厚和镀液稳定性差是关键瓶颈.文中研究了脉冲电流和镀液流动对铬电沉积的影响规律,发现两者均可促进电镀过程中生成的副产物向镀液主体的传递.然而,脉冲电镀会降低铬电沉积效率,镀液流动可以提高铬电沉积效率,并能促进铬镀层的持续增厚.在50mL/min的镀液流动条件下,直流电镀60min,可获得41μm的厚铬镀层,沉积速率为0.68μm/min,镀层表面平整致密.

Chrome plating is widely used due to excellent mechanical and anti-corrosion performance.However,the traditional hexavalent chromium plating process is highly toxic and polluting.The trivalent chromium plating process with low toxicity has received widespread attention.However,it is difficult to obtain thick chromium coating by trivalent chromium plating technology.Continuous plating and stable plating solution are the key issue.In this paper,the effects of pulse plating and bath flow on chromium electrodeposition were investigated.Both pulse current plating and bath flow can promote the transfer of by-products generated during the electroplating process.However,pulse plating will reduce the efficiency of chromium electrodeposition,and bath flow can enlarge the electrodeposition efficiency of chromium and promotes the formation of thick chromium.By bath flow with the rate of 50 mL/min,thick chromium coating with compact surface structure is obtained and the thickness is up to 41μm after 60 min plating.Deposition rate is up to 0.68μm/min.