BROMINE METHANOL ETCHANT PREPARATION FOR 690 NICKEL ALLOY 1

[79848598]

I try to find how prepare the BROMINE-METHANOL ETCHANT SOLUTION (BrMeOH) to perform a SEM over a 690 nickel alloy. I already look for in the ASTM E 407 and AMS handbooks without any luck.

Thanks in advance for any tip or reference.

 

[unclesyd]

Safety first!
Bromine is a very hazardous material. Read the MSDS and the Technical Data Sheet prior to using this material.

Check out the following:

http://www.metallography.com/

There was at one time a link that was devoted exclusively to metallurgical etchants, but my link is dead.

Also NiDI would be a great starting point.

One thing that I've found is that people tend not to recommend hazardous reagents as they once did.

 

[SMF1964]

I've had excellent luck with the mixed acids etch listed in ASTM 407 as I believe etch 89. It is a mixture of nitric, hydrochloric, acetic and glycerin. It does a great job etching grain boundaries, etc. The solution starts out pale yellow and darkens over time (minutes); the darker it gets, the stronger it gets.

For nickel alloys, let it stand for 4-5 minutes or so and then swab. Do not use after 30 minutes or so and do not store.

I agree with Unclesyd that hazardous etchants are not as popular now as they once were - I can't remember the last time someone used Murikami's...