I am preparing sample from commercially pure titanium(CP-Ti) to carry out metallography(O.M. test), which liquid should be used for polishing and which one for etching? My samples are cylindrical with diameter of 5mm, do they necessarily have to be mounted before them?
Thanks in advance
Based on ASTM E407-07 you can use enchants No. 186, and 187.
186 :10 mL HF, 5 mL HNO3, 85 mL water (Swab 3–20 s.)
187: 10 mL HF, 30 mL HNO3, 50 mL water (Swab 3–20 s.)
As for polishing I use OPS (SiO2-50 nm).
Hope this helps.
Here at LZN we use Steuers OP-U for polishing, I haven't had good experiences with OP-S as it seemed to make the specimen's surface porous. For etching, a colleague uses Kroll's reagent (ASTM E407-192). That's from experience I attached a file you may also find useful.
For Polishing: You have to start using SiC grid paper from 180 - 2000 grade. after that alumina polishing and it will be better if you go through the diamond polishing at last.
For etching: totally agree with Dr. Ahmad Zafari. Go through ASTM E407-07.
For mounting: Mounting basically used to hold the samples during polishing or any other metallographic sample preparation steps. If your sample dimension are enough to hold then no need to do any type of mounting. If it is not, go through the hot mounting with Bakelite which is more easy to make rather than the cold one, and also take less time. Hope this answer will help you in your experiments.
Thanks and regards
Soumyabrata
Dear Ahmad & Juan
Thank you for your helpful comments
I have found that the Kroll solution which is composed of as you stated is the most common one.
Dear Soumya
Thank you for your explanation
It seemed that mounting do not have to be performed , i hope so it works.
Best Regards
Hey Parham,
Actually Kroll's reagent is what we have suggested. Basically they are the same thing.
Cheers
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