脉冲电沉积SiC/TiN颗粒增强Ni-Mo纳米复合镀层研究  

SiC/TiN Particles Reinforced Ni-Mo Nanocomposite Coating Prepared by Pulse Electrodeposition

作　　者：徐义库[1] 范铭远 罗宇晴 赵秦阳 陈永楠[1] 郝建民[1] Xu Yiku;Fan Mingyuan;Luo Yuqing;Zhao Qinyang;Chen Yongnan;Hao Jianmin(School of Materials Science and Engineering,Chang’an University,Xi’an 710064,China)

机构地区：[1]长安大学材料科学与工程学院,陕西西安710064

出　　处：《稀有金属材料与工程》2021年第5期1656-1664,共9页Rare Metal Materials and Engineering

基　　金：中国留学基金委“青年学者出国留学计划”(201906565024);国家自然科学基金(51301021);中国博士后科学基金(2016M592730);中央高校基本科研业务费专项基金(300102318205,310831161020,310831163401,300102319304);长安大学创新与创业培训计划(201910710144);陕西省自然科学基金重点项目(2019JZ-27);陕西省陕煤联合基金(2019JLM-47)。

摘　　要：采用脉冲电沉积技术在6061铝合金表面制备SiC/TiN颗粒增强Ni-Mo纳米复合镀层。通过在镀层中引入SiC、TiN纳米颗粒并改变电沉积的平均电流密度和占空比,调控复合镀层的微结构,探讨纳米颗粒增强涂层的成膜过程与晶粒细化机理,研究复合镀层的组织结构与耐蚀性、耐磨性的关系。结果表明:双纳米颗粒的加入使镀层结构由锥状向胞状转变,晶粒尺寸由29.86 nm减小至22.79 nm。其中在电流密度为8 A·dm^(-2),占空比为20%时制备的镀层最为均匀致密且SiC/Ti N颗粒复合量最高,分别为1.3%和3.1%(质量分数)。镀层具有典型的fcc结构且呈现出(111)择优取向,纳米颗粒均匀分散在Ni-Mo基体中。Tafel极化和浸泡试验研究表明Ni-Mo复合镀层的腐蚀电流密度为7.08μA/cm^(2),相比之下在电流密度为4、8和12 A·dm^(-2)和占空比为40%、60%下制备的Ni-Mo/SiC-Ti N纳米复合镀层腐蚀电流密度分别为4.68、4.12、5.75、4.37和5.53μA/cm^(2),分别降低了34%、42%、19%、38%和21%。研究发现在电流密度为8 A·dm^(-2),占空比为20%下制备的纳米复合镀层表现出最好的耐蚀性。与Ni-Mo镀层相比,SiC/TiN颗粒的引入显著地提升了镀层耐磨性。此外,还对脉冲共沉积机理进行了讨论。A SiC/TiN particle reinforced Ni-Mo nanocomposite coating was prepared on the surface of 6061 aluminum alloy by pulse electrodeposition technique.By introducing SiC and TiN nanoparticles into the coating and changing the average current density and duty cycle of electrodeposition,the microstructure of the composite coating was adjusted,and the film formation process and grain refinement mechanism of the nanoparticle-enhanced coating were analyzed.The relationship between the microstructure of composite coating and the corrosion resistance and wear resistance was studied.The results show that the addition of double nanoparticles result s in a shift of the coating structure from conical to cellular,and the grain size is reduced from 29.86 nm to 22.79 nm.The coatings prepared at current density of 8 A·dm^(-2)are the most homogeneous and dense with the highest SiC/TiN particle complexes of 1.3 wt%and 3.1 wt%,respectively.The coating exhibits(111)preferred orientation and typical fee structure,with nanoparticles uniformly dispers ing in the Ni-Mo matrix.The corrosion behavior of the coatings was investigated by Tafel polarization and immersion test.Compared with the corrosion current density of Ni-Mo composite coating of 7.08μA/cm^(2),the corrosion current densities of Ni-Mo/SiC-TiN nanocomposite coatings prepared at current densities of 4,8,12 A·dm^(-2)and duty cycle of 40%and 60%are 4.68,4.12,5.75,4.37 and 5.53μA/cm^(2),which are reduced by 34%,42%,19%,38%and 21%,respectively.In particular,the nanocomposite coatings prepared at the current density of 8 A·dm^(-2)and the duty cycle of 20%exhibits the best corrosion resistance.Compared with Ni-Mo coating,the introduction of SiC/TiN particles significantly improves the wear resistance of the coating.In addition,the mechanism of pulsed co-deposition was discussed.

关 键 词：Ni-Mo镀层 脉冲电沉积 纳米颗粒 耐蚀性 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TG174.441[金属学及工艺—金属材料]