摘要
铝合金零件硫酸阳极氧化后表面出现发暗、发黑的非正常现象,影响产品质量和性能。采用扫描电子显微镜、金相分析等手段,经综合分析得出产生此弊病的主要原因是:包铝层厚度不均匀,在阳极氧化过程中合金基体被氧化,合金中的β相和Mg2Si相被优先溶解、(FeMn)Al6相不被氧化,使阳极氧化膜中出现夹杂和空洞所导致的。
It was found some times that defects of dim color with dark streaks appeared on local area of LF6M aluminum alloy parts surface after anodizing in sulphuric acid solution. These defects affect quality and performance of the product. Main causes for occurring this phenomenon were analyzed with methods of SEM and metallography. Experimental results revealed that if the thickness of the protective AI coating on the LF6M alloy surface was not uniform and there existed area where the protective Al coating was too thin to protect the LF6M alloy substrate from corrosion during the anodizing process. Then, the LF6M alloy substrate would be corroded during the anodizing of the parts. The β phase and Mg2Si phase in the alloy substrate were dissolved preferentially while the （FeMn）Al6 phase was remained undissolution. Thus holes and inclusions would be left in the substrate surface layer to form the defects of dim color with dark streaks on local area of the anodized LF6M aluminum alloy part surface.
出处
《电镀与精饰》
CAS
北大核心
2010年第4期40-43,共4页
Plating & Finishing
关键词
铝合金
金相组织
发黑
阳极氧化
aluminum alloy
metallographic organization
darkening
anodizing
