Corrosion phenomenon during surface treatment of aluminum profiles in LED tube housings

The aluminum ingots used in all aluminum profiles of our JE company are 6063 models. During the surface treatment of 6063 aluminum alloy profiles, it is sometimes found that there are different degrees of irregularly arranged dotted dark gray corrosion points on the surface of the aluminum profiles, excess and free. The 6003 aluminum alloy profile with more silicon has the following phenomena during surface treatment: when the profile is placed in an acid tank (sulfuric acid 15% to 20%), it can be clearly observed that there are many small bubbles on the surface of the profile. The temperature of the bath increases and the reaction speed becomes faster and faster, which indicates that the electrochemical corrosion of the primary battery has occurred [5]. At this time, if the profile is taken out of the tank for observation, many spots with different colors from the normal surface will be found on the surface of the profile. This dark gray corrosion point will be more obvious and intuitive when continuing to carry out subsequent treatments, such as alkali corrosion, acid neutralization light extraction and sulfuric acid anodizing.

There are some differences in appearance between the corrosion caused by zinc and the corrosion caused by silicon. The corrosion spots caused by zinc are like snowflakes, which spread out along the grain boundaries and are pits with a certain depth [6,7]. The corrosion points caused by silicon element are like inclusions of dark gray points, there is no outward diffusion along the crystal interface, and no depth is felt. And as the processing time prolongs, the number increases, and it does not stop until the complete reaction. This dark gray spot can be substantially eliminated or alleviated by prolonging the etching time or stripping treatment.

JE is a factory specializing in the production of LED tube housings, for more tube housings, please refer to:

https://www.jeledprofile.com/led-tube-housing

For more details, please contact: sales@jeledprofile.com

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