LY12CZ铝合金的代铬酸快速阳极氧化技术

通过在45 g/L的硫酸溶液中添加有机酸添加剂及快速成膜缓冲剂,以15~25 V的梯度电压方式对LY12CZ铝合金进行阳极氧化处理,获得一种代替铬酸阳极氧化、硼酸-硫酸阳极氧化工艺的铝合金新型环保快速阳极氧化工艺.对获得的氧化膜进行场发射扫描电子显微镜观察、耐点滴腐蚀试验、膜重试验以及疲劳性能测试.结果表明:有机酸、缓冲添加剂在铝合金硫酸阳极氧化成膜过程中可以缓冲硫酸对膜层的溶解,提高氧化膜层的致密性和耐腐蚀性能,同时降低了氧化过程对铝合金基体的疲劳损伤;另外,在15 V电压下氧化5 min再在25 V电压下氧化5 min,获得的氧化膜层性能与硼酸-硫酸工艺条件下15 V电压氧化20 min所获得的膜层性能相当,其中的有机酸添加剂为YP添加剂,快速成膜缓冲剂为YJ缓冲剂.

Rapid anodizing technology replacing chromic acid for LY12CZ aluminum alloy

Aluminum alloy anodizing coatings were prepared for LY12CZ in 45 g/L sulfuric acid solution through adding organic acid additive and buffering agent for fast film-forming, with the gradient voltage of 15-25 V, to replace the traditional chromic acid anodizing and boric-sulfuric acid anodizing. The field emission scanning electron microscope, titrating test, coating mass test and fatigue test were used to evaluate the properties of the anodizing coatings. The results show that organic acid additive and buffering agent for fast film-forming can relieve the dissolution of anodizing coatings, improve the compactness and corrosion resistance and reduce the fatigue damage during the anodizing process. Moreover, the properties of coatings anodized in the new anodizing solution of sulfuric acid, organic acid and buffering agent with the voltage of 15 V for 5 min and of 25 V for 5 min are equal to ones anodized in boric-sulfuric acid with the voltage of 15 V for 20 min. Organic acid additive is YP additive and buffering agent for fast film-forming is YJ additive.