CAJ | 학술논문

研究了以硫酸镍为主盐的AZ91D镁合金化学镀镍.采用无铬前处理在AZ91D镁合金表面形成高锰酸盐和磷酸盐化学转化膜,用SEM、EDX、XRD和极化曲线等方法研究化学转化膜和化学镀镍层的形貌、组成及在3.5%的NaCl溶液中的耐腐蚀性能.结果表明,在高锰酸盐转化膜表面形成的化学镀镍层呈胞状,较致密,有微裂纹;在磷酸盐转化膜上形成的化学镀镍层也呈胞状,晶胞大小不均匀,没有微裂纹.镀层厚度均匀,致密,无孔隙.在3.5%的NaCl溶液中的极化曲线表明化学转化膜对镁合金基体的耐腐蚀性能提高不大,经高锰酸盐和磷酸盐前处理的化学镀镍层腐蚀电位分别为-0.48V_(SCE)和-1.12 V_(SCE).以硫酸镍为主盐的经磷酸盐前处理的化学镀镍层较好地提高了镁合金的耐腐蚀性能.
연구료이류산얼위주염적AZ91D미합금화학도얼.채용무락전처리재AZ91D미합금표면형성고맹산염화린산염화학전화막,용SEM、EDX、XRD화겁화곡선등방법연구화학전화막화화학도얼층적형모、조성급재3.5%적NaCl용액중적내부식성능.결과표명,재고맹산염전화막표면형성적화학도얼층정포상,교치밀,유미렬문;재린산염전화막상형성적화학도얼층야정포상,정포대소불균균,몰유미렬문.도층후도균균,치밀,무공극.재3.5%적NaCl용액중적겁화곡선표명화학전화막대미합금기체적내부식성능제고불대,경고맹산염화린산염전처리적화학도얼층부식전위분별위-0.48V_(SCE)화-1.12 V_(SCE).이류산얼위주염적경린산염전처리적화학도얼층교호지제고료미합금적내부식성능.
Electroless nickel-plating on AZ91D magnesium alloy by using NiSO_4·6H_2O as main salt was described. Permanganate and phosphate chemical conversion films were proposed as the chrome-free pretreatment layer between electroless nickel-plating and AZ91D magnesium alloy substrate. Morphology, composition and corrosion resistance of the chemical conversion film and electroless nickel-plating layer in 3.5%NaCl solution were determined by SEM, EDX, XRD and polarization curve. The results show that the electroless nickel-plating coating after permanganate pretreatment exhibits cell structure with sound to some extent and micro-crack, while one after phosphate pretreatment also exhibits cell structure with uneven grain size and micro-crack free, and plating coating shows uniform thickness with compact structure and pore-free. Corrosion resistance is slightly improved by chemical conversion treatment compared with that of magnesium substrate, and corrosion potential of electroless nickel-plating coating after permanganate pretreatment and phosphate pretreatment reach -0.48V_(sce) and -1.12V_(sce), respectively, in 3.5%NaCl solution by polarization curves. Corrosion resistance of AZ91D magnesium alloy is improved by electroless nickel-plating layers after phosphate pretreatment with NiSO_4·6H_2O as main salt.