Study Of Color Degradation Of Dyed Anodic Oxidation Films Of Aluminum Alloy Used In A Brand Of Rifle

In order to improve appearance of rifles made from aluminum alloy and solve problems of color degradation in use, researches in natural environment and in laboratory with accelerated conditions were conducted. The two sites, Jiangjin and Wanning, were chosen as test stations to test the behavior of anodic oxidation films of the rifle receiver exposed to outdoors, and simulated environmental tests at laboratory were chosen to research the light fasting of aluminium alloy oxide films of rifle receiver. In order to find primary environmental factors which influence color degradation of dyed anodic oxidation films, find mechanism of color degradation and establish fast evaluation method for light fasting of alumina films, Scanning Electron Microscope and Scanning Tunnelling Microscope were used to observe appearance-changing of alumina films before and after test. Ultraviolet Visible Light Absorption Spectroscopy and Infrared Spectroscopy were also used to test and analyze group-changing of dyes used for organic dyeing and dyes which dissolved out from alumina films of sample after test. Based on results of tests and observation, the following conclusions have been obtained.(1) At Jiangjin and Wanning test stations, the environmental corrosion resistance of aluminum alloy anodic oxidation samples dyed with organic dyeing was qualified. The primary failure of the sample is color degradation.(2) At outdoors exposure tests at Jiangjin and Wanning test stations, the light fasting of the sample which was dyed with organic dyeing was not good, but the sample which was dyed with metal compound electrolysis dyeing technology show a quite stable color maintenance. So the metal compound electrolysis dyeing is a way to solve the problem of color-changing for aluminium alloy rife receiver.(3) The primary environmental factor for color degradation of aluminium alloy anodic oxidation film is illumination. Only the factor of salt fog can't cause color degradation of aluminium alloy anodic oxidation film. However, if it cooperates with illumination, color degradation would be accelerated.(4) The rupture of "-N=N-" in organic dye molecules in the aluminium alloy anodic oxdation film was the primary rea.,on for color degradation of dyed aluminium alloy anodic oxidation film. And the corrosion caused by pitting can enlarge the pores of the Al2O3 film. It in turn leads to the dye in the film running off. In this cause, colordegradation of alumina film would be speed up.(5) Light aging accelerated test is correlative favorably with exposure test at outdoors. And it is acceptable to evaluate color degradation of aluminium alloy anodic oxidation film dyed used for organic dyeing at outdoors to a certain extent.