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After tumbling of titanium, how to remove oxides for brighter anodizing

January 26, 2014

Q. We manufacture medical titanium parts. We are facing the following problem:
As part of the manufacturing process, we place our titanium (6al4v) parts in a tumbler with a burnishing solution to remove burrs and round up sharp edges. The process works well. However, the part emerges with a darker color (coating). We think it is titanium oxide. When we anodize the part the color is obviously darker. In some cases the laser marking is barely visible.

We need to find out a way to remove this "oxide micro crust" after the tumbler process and before we anodize so that colors are brighter and marking is visible. Is there a way of accomplishing this? We have electropolishing machines. Is there some sort of commercial solution so we can use with our equipment?

Additionally, if you happen to know where we can buy some passivation chemicals to use with titanium, we would appreciate the reference.

Thanks,

Ricardo Romero
- Caracas, VENEZUELA