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PICKLING OF HEAT TREATED TITANIUM

At present we pickle Titanium using Nitric/hydrofluoric acid mixture. However it takes a long time to remove the oxide layer after the ti has been heat treated. Is there a better pickling solution to remove the Ti oxide layer.

Graham Best
an aerospace company - Chester, Cheshire, England
2003

Can you provide some more information on the alloy type, exact fabrication method (cold forming sheet? hot forging bar?), lubricants or coatings that may be used, and temperature used for heat treating? The 10:1 mixture of nitric acid with hydrofluoric acid is the best for pickling, but if you may need to use a molten alkaline-based salt bath or a mechanical operation (sand or bead blasting, belt grinding, etc.) if a complex scale is present due to interaction of lubricants with oxide layer.

Toby Padfield
- Michigan
2003

Clean the parts better just before they go into the oven. A properly maintained vacuum furnace is the best answer. Do you check the dissolved Ti content? The etch rate goes way down at about 10 grams/L, and essentially stops at 15g/L. Even with a high HF percentage.

James Watts
- Navarre, Florida
2003

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There is less hazardous method of titanium oxide removal. We use it when oxide layer forms during titanium electropolishing due to heat generated on the surface of polished titanium.

Anna Berkovich
Russamer Lab

Pittsburgh, Pennsylvania

2003