Etching Titanium aluminide

[Materialist25]

Hi there,

I got a problem with etching a titanium aluminide alloy. The material I got kinda goes like this Ti/Ti3Al/TiAl (probably with a good deal of oxygen) and I want to see the microstructure in the aluminides.

I already tried kroll etchant, but that only etched a little bit of the Ti phase. I'd really appreciate it if somebody could tell me why kroll doesn't work and if there is an alternative. Maybe it has something to do with an alphacase because of the oxygen?


Thank you very much!

 

[Materialist25]

Okay after trying a little more it kinda works with Kroll, but I don't really understand the results yet. Can somebody give me a link or explain how the Kroll etchant contrasts the sample? Does something etch faster or what is the general principle behind the etching?

 

[CoryPad]

http://books.google.com/books?id=GR...tanium+alpha+beta+kroll+etch&output=html_text

 

[Ron]

Try heating the Kroll's reagent to about 150F and immersing sample for 10 to 20 seconds rather than swabbing. Adjust immersion time as necessary.