电喷镀镍—磷—氮化硼复合镀层工艺及其性能研究

发布时间：2018-07-06 12:58

  本文选题：电喷镀 + Ni-P-BN(h)复合镀层　； 参考：《南京农业大学》2015年硕士论文

【摘要】：电镀是改善基体金属表面质量的一种常用而有效的方法,电喷镀技术作为在传统电镀基础上发展起来的表面电沉积新技术,大大提高了沉积速度,且制备的镀层表面质量良好。有着"白色石墨"之称的BN,其抗氧化性、化学稳定性、自润滑性较好,采用纳米BN(h)颗粒与金属共沉积的方法制得的Ni-P-BN(h)复合镀层,整体上具有优于普通Ni-P合金镀层更好的物理、化学性能,具有很大的应用前景。本文在自行研制的数控电喷镀装置上制备Ni-P-BN(h)复合镀层,分析工艺参数的影响规律,并对镀层性能进行检测,具体包括以下几方面的内容:(1)表面活性剂的选择和BN(h)颗粒浓度的确定。开展单因素试验,通过不同表面活性剂制得的复合镀层的Zeta电位、BN(h)颗粒悬浮稳定性及表面形貌检测,得出表面活性剂应选择十六烷基三甲基溴化铵(CTAB);通过不同BN(h)颗粒浓度下制得的复合镀层的表面形貌、显微硬度及表面粗糙度比较,得出BN(h)颗粒浓度应为10g/L。(2)电喷镀Ni-P-BN(h)复合镀层的计算机仿真研究。采用ANSYS软件和FLUENT软件对加工区域的电场和流场进行二维仿真分析,得出采用不对称的单边刃口型喷嘴可得到均匀镀层,且选择了合适的镀液流速,为电喷镀试验做准备。(3)电喷镀Ni-P-BN(h)复合镀层的工艺试验研究。采用JMP定制设计器进行试验设计及数据回归分析,研究电压、镀液温度、两极相对间隙、两极相对运动速度对复合镀层沉积速度、显微硬度、表面粗糙度的影响,并将各响应与电喷镀Ni-P合金镀层进行比较。利用期望函数法进行多响应优化,得到最优工艺参数组合为:电压16V,镀液温度63℃,相对间隙1.3mm,两极相对运动速度135mm/min;此工艺条件下测得镀层的平均沉积速度为49.27μm/min,显微硬度为673.19Hv,表面粗糙度为0.216μm。(4)电喷镀Ni-P-BN(h)复合镀层的摩擦磨损性能研究。采用摩擦系数测定、磨损量计算及磨痕表面形貌检测,得出Ni-P-BN(h)复合镀层具有高于Ni-P合金镀层、远高于45钢的耐磨性,并探究了磨损机制。(5)电喷镀Ni-P-BN(h)复合镀层的耐腐蚀性能研究。采用动电位扫描测定极化曲线的方法及腐蚀后表面形貌的检测,计算镀层在质量分数3.5%的NaCl溶液中的腐蚀电位和腐蚀电流,得出Ni-P-BN(h)复合镀层具有高于Ni-P合金镀层的优良耐蚀性,并分析了腐蚀机理。
[Abstract]:Electroplating is a common and effective method to improve the surface quality of substrate metal. As a new surface electrodeposition technology developed on the basis of traditional electroplating, electrospray plating technology greatly improves the deposition rate and the surface quality of the coating is good. BNs, known as "white graphite", have better oxidation resistance, chemical stability and self-lubricity. Ni-P-BN (h) composite coatings prepared by co-deposition of nano-BN (h) particles with metals have better physical properties than ordinary Ni-P alloy coatings on the whole. The chemical properties have great application prospect. In this paper, Ni-P-BN (h) composite coating was prepared on the NC electrospray plating device, the influence of process parameters was analyzed, and the performance of the coating was tested. The main contents are as follows: (1) selection of surfactant and determination of concentration of BN (h) particles. The suspension stability and surface morphology of Zeta potential BN (h) particles of composite coatings prepared by different surfactants were tested by single factor test. It is concluded that cetyltrimethylammonium bromide (CTAB) should be selected as surfactant, and the surface morphology, microhardness and surface roughness of the composite coating prepared by different concentration of BN (h) particles are compared. The results show that the concentration of BN (h) particles should be 10 g / L. (2) computer simulation of Ni-P-BN (h) composite coating by electrospray plating. By using ANSYS software and fluent software, the electric field and flow field in the machining area are simulated and analyzed. It is concluded that the uniform coating can be obtained by using asymmetrical one-sided edge nozzle, and the appropriate velocity of plating bath is selected. (3) study on the process of electrospray plating Ni-P-BN (h) composite coating. The effect of voltage, bath temperature, relative gap between two poles, relative velocity of two poles on deposition speed, microhardness and surface roughness of composite coating was studied by using JMP custom designer and data regression analysis. The response of Ni-P alloy coating was compared with that of electrospray plating. The optimum process parameters are as follows: voltage 16V, bath temperature 63 鈩，

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