抗垢耐腐蚀Ni-P-亚微米Sn复合镀层的制备及性能研究

发布时间：2018-04-08 20:44

本文选题：亚微米Sn　切入点：Ni-P化学镀　出处：《江苏大学》2017年硕士论文

【摘要】：抗垢耐磨耐腐蚀的Ni-P镀层在热能、石油、化工等诸多领域具有广泛的应用背景。本文首次提出低表面能和高电子释放能力协同效应,利用Ni-P镀层本身具有的低表面能和金属Sn颗粒拥有的较强电子释放能力,开发出耐腐蚀和抗垢于一体的Ni-P-亚微米Sn复合镀层,具体的研究工作和取得的成果如下:用非离子型OP-10表面活化剂和超声波分散及施镀过程机械搅拌的综合办法来处理Sn颗粒的团聚问题,超声波分散时间为2h。采用L16(45)正交试验方案,得出最佳的工艺参数,即NiSO_4·6H_2O取26g/L;NaH_2PO_2·H_2O取24g/L;OP-10取100mg/L;Sn含量取2g/L;C_6H_8O_7·H_2O取15g/L;C_3H_6O_3取3g/L;CH_3COONa取6g/L;PH取5.4;机械搅拌速度为200r/min;控制温度90℃。Sn颗粒在镀层中分布均匀,Ni、P、Sn的含量分别达到了60.61%、8.04%、9.88%,复合镀层的结合力为30N。亚微米Sn加入到Ni-P镀层中,有助于晶粒的细化,组织更加致密,从而提高了镀层的硬度,经过相同的热处理后,Ni-P-亚微米Sn复合镀层的硬度值均高于Ni-P镀层硬度,热处理300℃下,硬度达到最高值1072.4HV。XRD分析表明:镀态下的Ni-P-亚微米Sn复合镀层为非晶态结构,经过500℃热处理后,镀层的结构逐渐转变为含有Sn、Ni_5P_4、Ni_2P、Ni_3P、Ni_5P_2、Ni_2P等多个相的晶态结构。镀层的摩擦磨损测试表明:Ni-P-亚微米Sn复合镀层的摩擦系数0.382比Ni-P镀层的摩擦系数0.455降低了16.04%,耐摩擦性能更好。当Sn含量为6g/L时,复合镀层的耐磨性最好,可见并不是Sn含量越多,对镀层的耐磨性越好。随着热处理温度的提高,复合镀层不断的晶化,硬度提高,抵抗塑性变形和摩擦力的能力提高,增加了耐磨性,热处理300℃下,Ni-P-亚微米Sn复合镀层有着最佳的耐磨性。均匀腐蚀实验表明:在5%H_2SO_4和3.5%NaCl中,Ni-P-亚微米Sn复合镀层的抗腐蚀性能比起Ni-P镀层分别提高了26.32%和51.1%,比起Q235提高了近45%;电化学腐蚀测试表明,Ni-P-亚微米Sn复合镀层的自腐蚀电位比起Ni-P镀层更正,自腐蚀电流更低,耐腐蚀性能更好。复合镀层的交流阻抗参数与Ni-P镀层和基体材料相比,传荷电阻值更大,电容值更小,孔隙率更低,耐腐蚀性能更好,当Sn的含量为2g/L时,Ni-P-亚微米Sn复合镀层抗腐蚀性是最好的,随着Sn颗粒含量的增加,镀层的孔隙率也随之增大,复合镀层的耐腐蚀性能越来越差。热处理200℃时Ni-P-亚微米Sn复合镀层的耐腐蚀性最好,400℃时最差,热处理改变了镀层的组织结构,从而改变了镀层的耐腐蚀能力。Ni-P-亚微米Sn复合镀层的污垢增重明显低于Ni-P镀层和Q235基体,与Q235基体相比,复合镀层的抗垢性能提高55%;与Ni-P镀层相比,复合镀层抗垢性能提高了46%。Ni-P-亚微米Sn复合镀层的接触角最大,达到了120.2°,表面自由能的计算,也得出复合镀层具有最小的表面自由能,为15mJ/m~2,接触角和表面自由能的计算都充分说明了亚微米Sn的加入有利于提高镀层的抗垢性能。流速对于镀层抗垢性能的影响,是扩散、沉积作用和剥蚀作用的结合。流速较低时,扩散起主导作用;流速较大时,剥蚀起主导作用。转速从350r/min提高到550r/min时,污垢的增重是显著的提高;当转速由550r/min提高到750r/min时,污垢的增重反而下降,甚至比350r/min时的增重还要低。温度越大,微溶性盐溶解度降低,污垢沉积量也随之增加。随着亚微米Sn含量的增加,复合镀层表面的自由能值也随着增大。镀层表面的污垢沉积也逐渐覆盖整个表面,呈现棉絮状分布,污垢沉积量逐渐增大,抗垢性能随之减小,Sn含量为2g/L时,制备的复合镀层抗垢性能做好。
[Abstract]:Ni-P anti fouling coating wear resistance corrosion resistance in heat, oil, is widely applied in many fields such as chemical industry. This paper first proposed the low surface energy and high electron releasing ability of synergistic effect, strong electron releasing ability by Ni-P coating has low surface energy and metal particles with Sn, developed the Ni-P- sub micron Sn composite the coating corrosion resistance and anti fouling in one of the specific research work and achievements are as follows: the problem of dispersion and application of a comprehensive approach to deal with the mechanical stirring plating process of Sn particles with nonionic surfactant OP-10 and ultrasonic, ultrasonic time is 2h. by L16 (45) orthogonal test scheme, the process the best parameters of NiSO_4 6H_2O 26g/L NaH_2PO_2 H_2O; 24g/L; OP-10 100mg/L; Sn 2g/L C_6H_8O_7 H_2O content; 15g/L; C_3H_6O_3 3g/L; CH_3COONa 6g/L; PH 5.4; mechanical stirring Mixing speed is 200r/min; the control temperature of 90.Sn particles are uniformly distributed in the coating, Ni, P, Sn were respectively 60.61%, 8.04%, 9.88%, the binding force of composite coating was added to the Ni-P 30N. sub micron Sn coating, contributes to grain refinement, more compact structure, and to improve the the hardness of the coating after heat treatment, the same, Ni-P- sub micron Sn composite coating hardness values were higher than the Ni-P hardness, heat treatment at the temperature of 300 DEG C, the hardness reaches the highest value of 1072.4HV.XRD analysis showed that Ni-P- sub micron plated Sn composite coating is of amorphous structure, after 500 DEG C after heat treatment, coating structure gradually transforms to contain Sn, Ni_5P_4, Ni_2P, Ni_3P, Ni_5P_2, Ni_2P and other phases of the crystal structure. The friction and wear test showed that the friction coefficient of Ni-P- coating sub micron composite coating Sn 0.382 than the friction coefficient of Ni-P coating 0.455 is reduced by 16.04%, wear resistance Better. When the Sn content is 6g/L, the wear resistance of the composite coating is the best, not seen the increasing of Sn content, the better wear resistance of the coating. With the increase of heat treatment temperature, crystallization, continuous composite coating hardness, resistance to plastic deformation and friction increase, increased wear resistance, heat treatment at 300, Ni-P- sub micron Sn composite coatings have excellent wear resistance. That uniform corrosion experiment in 5%H_2SO_4 and 3.5%NaCl, Ni-P- sub micron Sn composite coating corrosion resistance than Ni-P coating were increased by 26.32% and 51.1%, compared to Q235 increased by nearly 45%; electrochemical corrosion tests show that the corrosion potential than Ni-P coating correction Ni-P- sub micron Sn composite coating, the corrosion current is lower corrosion resistance. The composite coating of impedance parameters compared with the Ni-P coating and the substrate, charge transfer resistance is large, the capacitance is smaller, Lower porosity, better corrosion resistant performance, when the content of Sn is 2g/L, Ni-P- sub micron Sn composite coating corrosion resistance is the best, with the increase of Sn particle content, the porosity of the coating increases, the corrosion resistance of composite coating is more and more poor. Heat treatment at 200 DEG Ni-P- sub micron Sn composite coating the best corrosion resistance, 400 degrees is the worst, the heat treatment to change the coating microstructure, thus changing the coating corrosion resistance of the.Ni-P- sub micron Sn composite coating dirt weight was significantly lower than that of Ni-P coating and Q235 substrate, compared with the Q235 matrix, anti fouling performance of composite coating increased by 55% compared with Ni-P; coating, anti fouling properties of the composite coatings increased 46%.Ni-P- sub micron Sn composite coating the contact angle, reached 120.2 degrees, the calculation of surface free energy, also obtained composite coating has the minimum surface free energy of 15mJ/, m~2, contact angle and surface Calculation of surface free energy are fully illustrated with sub micron Sn can improve the anti fouling property of the coating. The diffusion effect, velocity for anti fouling coatings, combined with sedimentation and denudation. The flow rate is low, diffusion plays a leading role; the flow rate is larger, erosion plays a leading role from the speed. 350r/min increased to 550r/min, the dirt weightening is remarkably increased; when the speed is increased from 550r/min to 750r/min, the dirt weight decreased, even more than 350r/min when the weight is still lower. The greater the temperature, slightly soluble salt solubility is reduced, the dirt deposition increases. With the increase of sub micron Sn the content of the composite coating, the surface free energy value with the increase of fouling deposition on the surface of the coating. It gradually cover the entire surface, showing the distribution of cotton wool, dirt deposition increases, anti fouling properties decreased, Sn content is 2g/L, preparation The anti scaling property of the composite coating is done well.

【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG174.4

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