Ni-cBN复合镀层制备工艺参数对性能的影响

Effect of preparation parameters on properties of electrodeposited Ni-cBN composite coatings

采用复合电镀技术在黄铜基体上制备Ni-cBN复合镀层;研究添加和未添加CTAB界面活性剂、镀浴pH值、电流密度、镀浴中cBN微粉浓度、搅拌速度等参数对复合镀层微观组织、显微硬度和耐磨性的影响。结果表明:添加CTAB能显著提高复合镀层耐磨性,并且随着镀层cBN共析量和分散性的增加复合镀层的耐磨性提高;适宜的工艺条件如下:CTAB添加量为0.15 g/L,镀浴pH值为3,电流密度为4 A/dm2,搅拌速度为550 r/min,镀浴中cBN浓度为2.5 g/L。统计分析结果表明:复合电镀参数间相互影响很大,未添加CTAB时,电流密度与搅拌速度相互影响最显著;添加CTAB后,电流密度与pH值的相互影响、镀浴中cBN微粉含量与搅拌速度的相互影响最显著。

The composite coatings of Ni and nano/microsized cBN particle were prepared on Cu substrate using the co-electrodeposition process.The effects of the process variables such as the addition of the CTAB surfactant,pH value,current density,cBN content in the bath and stirring speed of the bath on the microstructure,hardness and abrasion resistance of the coatings were studied.The results indicate that the abrasion resistance for the Ni-cBN film increases with the cBN content in the coating and the film grown in the CTAB-containing bath has greater abrasion resistance than the one without CTAB due to the dispersing effect of CTAB.The suitable operation conditions were found to be as follows: CTAB content of 0.15 g/L in the bath,pH value of 3 in the bath,current density of 4 A/dm2,stirring speed of 550 r/min,cBN content of 2.5 g/L in the bath.In addition,the statistics analysis shows that the interaction effects among the process variables are apparent.The interaction effect between the current density and the stirring speed is the highest for the no CTAB-containing bath,while the interaction effects between the current density and pH value and between the cBN content in the bath and stirring speed are obvious for the CTAB-containing bath.