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  1. skylerf

    Clear Anodizing Producing Poor Finish

    Sanding is not bad, but you should know that sometimes the anodizer's pretreatment system will bring out or highlight the stratches. Its important to work your way into the finer grits of sandpaper. Don't jump from rough grit straight into a super fine grit. We use vibratory tumbling with...
  2. skylerf

    Clear Anodizing Producing Poor Finish

    We anodize Type II, class 1. After examining the pictures, I would say that it looks pretty bad. I don't think it is a material problem. 6061-T6 is very common to anodizer, and anodizes well. It could be a surface contaminent that is interfering with the finish. Maybe their pretreament or...
  3. skylerf

    Citric Acid Passivation Of Laser Etched Stainless Steel

    We currently laser etch stainless steel (17-4) for medical applications. After laser etching, we follow with Type II nitric acid passivation at ambient condition/temperature. The intent of the passivation is to remove free iron from laser etched area, which could create a rusting issue if left...
  4. skylerf

    When Should one specify Pickling and passivation?

    I agree that Nitric Acid is a strong oxidizer, which does produce the Cr oxide layer in cycle, but Cr will naturally oxidize with oxygen from the atmosphere. So, is it necessarly a requirement that a passivation process produce a Cr oxide layer for the surface of the material to be passive? Or...
  5. skylerf

    When Should one specify Pickling and passivation?

    Some interesting replies. Let me throw my two cents into the ring. I don't understand why a print would state pickle and passivation in the same note. Normally pickling is used to remove heat treat scale by solublizing the scale/metal in a strong acid bath. Since metal is soluble in the...
  6. skylerf

    Bright dipping extruded aluminum part

    Don't think so. Normally a bright dip process is an acid which creates a shine similiar to electropolishing stainless steel. It evens the surface roughness, which creates the polish finished. The way it accomplishes this task is attacking the aluminum surface. Normally, this type of...
  7. skylerf

    graphite in forging lubricants

    Although I do not work at a forging house, I have visited and asked the same question. I believe the graphit is used as a releasing agent. when the heated metal is stamped, it will stick to the dye. the graphit helps release the forged part from the dye. i had an issue with aluminum forged...
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