化学镀Ni-B镀层对Al-Cu-Mg合金组织和腐蚀性的影响  

Effect of Electroless Plated Ni-B Coating on Microstructure and Corrosion Proerties of Al-Cu-Mg Alloy

作　　者：陈来[1] 刘志义[1] 林亮华[1] 杨荣先 

机构地区：[1]中南大学材料科学与工程学院,湖南长沙410083

出　　处：《热加工工艺》2016年第8期176-179,共4页Hot Working Technology

基　　金：国家自然科学基金项目(51171209)

摘　　要：采用化学镀法在Al-Cu-Mg合金表面制备Ni-B镀层,通过扫描电镜(SEM)及X射线衍射分别对镀层形貌及结构进行了分析。研究了在3.5%Na Cl溶液中Ni-B镀层对Al-Cu-Mg合金腐蚀形为的影响。结果表明,Ni-B镀层为结构致密的非晶合金,经热处理后镀层发生明显晶化转变,分解成面心立方(fcc)Ni相及大量的Ni_3B相,使镀层硬度明显提高。在腐蚀介质中,Ni-B镀层较Al-Cu-Mg合金腐蚀电流密度降低近一个数量级。Ni-B镀层试样的腐蚀过程主要由电荷传递过程控制,且未发现微孔腐蚀现象,因此可有效阻碍腐蚀液对基体的直接侵蚀从而提高Al-Cu-Mg合金的耐腐蚀性。Ni-B alloy coating was deposited on A1-Cu-Mg alloy by electroless nickel plating. The surface morphology and structure of Ni-B coating were analyzed by using SEM and XRD, respectively. The influence of Ni-B coating on the corrosion behavior of A1-Cu-Mg alloy was investigated. The results show that electroless Ni-B co ating with low porosity is amorphous and crystallized to large amount of face centered cubic （fcc） Ni and Ni3B phase after heat treatment at 300℃ for 1 h, which can significantly increase its surface microhardness. The corrosion current density of Ni-B coating is about one order lower than that of Al-Cu-Mg alloy in corrosion medium. The corrosion process is controlled by charge transfer step with no evidence of pitting corrosion, hence, the corrosion resistance of Al-Cu-Mg alloy improves by protecting the substrate from the erosion of NaC1 solution.

关 键 词：AL-CU-MG合金 化学镀 Ni-B镀层 耐腐蚀性 

分 类 号：TG146.2[一般工业技术—材料科学与工程] TG174[金属学及工艺—金属材料]