Ni基复合镀层的制备工艺及其在海水中的防腐性能研究

发布时间：2019-03-16 15:38

【摘要】：通过化学镀的方法制备了双层Ni-P、Ni-P/Ni-Zn-P复合镀层和Ni-P-SiO_2复合镀层的试样,考察了Ni-P、Ni-Zn-P基础镀液配方中络合剂和缓冲剂对镀层的影响;深入研究了复合镀层的施镀工艺对镀层表面组织形貌、断面形貌和成分的影响,并探究了单层镀层和复合镀层耐蚀性。通过实验研究,得到以下结论。在制备双层Ni-P(中-高磷)复合镀层时,当内层中磷Ni-P镀层施镀10~20min,外层高磷Ni-P合金镀层施镀60min时,随内层施镀时间增加,内层镀层厚度增加,内外层镀层厚度比减小,镀层总厚度减小。当内层施镀时间30min,外层施镀时间60min时,无法得到双层Ni-P复合镀层。在制备双层Ni-P/Ni-Zn-P复合镀层时,当内层Ni-P镀层施镀5~10min,外层Ni-Zn-P合金镀层施镀60min时,无法得到双层Ni-P/Ni-Zn-P复合镀层。当内层Ni-P镀层施镀20min,外层Ni-Zn-P合金镀层施镀60min时,得到了总厚度约7.5μm的双层Ni-P/Ni-Zn-P复合镀层,其中内层镀层的厚度约2.3μm,P含量约为9%,Ni含量约在86%;外层镀层厚度约5.2μm,Zn含量约为5%,P含量约为11%,Ni含量约在84%,内外层的厚度比约1:2。在制备Ni-P-纳米SiO_2复合镀层时,随着纳米SiO_2添加量的增加,Ni-P-SiO_2复合镀层表面胞状结构尺寸逐渐减小,且排列更加紧凑,镀层更为平整致密,从而能够提高镀层的耐蚀性;而且硬度随着纳米SiO_2添加量的增加呈现逐渐上升的趋势。在NaCl、H_2SO_4溶液中复合镀层腐蚀速率明显低于合金镀层,能够更好的提高基体材料的耐蚀性。由于复合镀层能够明显提高镀层的致密度,降低镀层的孔隙率;并且双层复合镀层中内层与外层之间能够形成原电池,从而能够更好的保护基体。
[Abstract]:The samples of double layer Ni-P,Ni-P/Ni-Zn-P composite coating and Ni-P-SiO_2 composite coating were prepared by electroless plating, and the Ni-P, was investigated. The effect of complexing agent and buffer agent on the coating in the formulation of Ni-Zn-P basic plating bath; The effect of plating process on the surface morphology, cross-section morphology and composition of composite coating was studied, and the corrosion resistance of single-layer coating and composite coating was also investigated. Through the experimental study, the following conclusions are obtained. When the double layer Ni-P (medium-high phosphorus) composite coating is prepared, when the inner layer is coated with phosphorus Ni-P coating for 10 min and the outer layer with high phosphorus Ni-P alloy coating with 60min coating, the thickness of the inner layer increases with the increase of the plating time in the inner layer, and the thickness of the coating increases with the increase of the plating time in the inner layer. The thickness ratio of the inner to outer layer decreases, and the total thickness of the coating decreases. When the plating time is 30 min in the inner layer and 60min in the outer layer, the double layer Ni-P composite coating can not be obtained. During the preparation of double-layer Ni-P/Ni-Zn-P composite coating, the double-layer Ni-P/Ni-Zn-P composite coating could not be obtained when the inner Ni-P coating was applied for 5 min and the outer Ni-Zn-P alloy coating was coated with 60min. A double layer Ni-P composite coating with a total thickness of 7.5 渭 m was obtained when the coating was coated with 60min for 20 min and Ni-Zn-P alloy coating for 20 min, in which the thickness of the coating was about 2.3 渭 m and the P content of the coating was about 9%. The content of Ni was about 86%; The thickness of the coating is about 5.2 渭 m, the content of Zn is about 5%, the content of P is about 11%, the content of Ni is about 84%, the thickness ratio of inner and outer layer is about 1 m2. In the preparation of Ni-P- nano-SiO_2 composite coating, with the increase of nano-SiO_2 content, the cellular structure size of Ni-P-SiO_2 composite coating decreases gradually, and the arrangement is more compact, and the coating is more flat and compact. Therefore, the corrosion resistance of the coating can be improved. The hardness increased with the addition of nano-SiO_2. The corrosion rate of the composite coating in NaCl,H_2SO_4 solution is obviously lower than that of the alloy coating, and the corrosion resistance of the matrix material can be improved better than that of the alloy coating. Because the composite coating can obviously improve the density of the coating and reduce the porosity of the coating, the original battery can be formed between the inner layer and the outer layer of the double-layer composite coating, so that the matrix can be better protected.
【学位授予单位】：华北理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG174.4

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