Effective Removal of Titanium from Tantalum Crucibles: Tips and Techniques

[12stCDB]

I'm trying to find a way to remove a non-negligable amount of titanium from a tantalum crucible. I've removed as much as possible with tweezers, but there is still a reasonable amount in the crucible. I know that titanium is soluble in certain acids (hydrofluoric, sulfuric), but it's my understanding that tantalum is generally soluble under the same conditions.

If anyone has experience with this and can advise me on removing the titanium without damaging the crucible, I would very much appreciate it.

 

[Hyo X]

What is the crucible for?
Ti melting temp: 1941
Ta melting temp: 3290 K

heat it up a lot, upside down? or while under exposure to incident energy source to induce Ti atom desorption.

 

[citw]

One issue is that the melting temperature isn't really the relevant quantity so much as the vapor pressure (correct me if I'm wrong). My understanding is that within the low growth pressure range tantalum should start to evaporate at temperature around 1800 C, while titanium should evaporate in the 1500-1600 C range.

I think this is going to be a waste of time in the end, since there's no way of knowing whether or not all of the titanium has been removed from the crucible. Looks like we'll need to spring for a new crucible.