look at pic attached. i used (solution A: 7ml HCl, 10ml H2SO4, 10ml HF,10ml HNO3, 10ml H2O. solution B: 20ml solution A, 20ml HCl, 10ml HF and 0.5gr CuCl2.2H2O) time etching: 5min solution A then 5min solution B. in pic porosity in structure is manifest. incidentally i used (10ml HCl and 1ml H2O2) but result was not okay. please help me.
Take a picture after polishing and after etching. I think you may have badly prepared sample or you have some residue after etching (some of "porosity" lies along scratches).
On the basis of a previous question you asked relating to the microstructure of Haynes 188 alloy where the sample was almost free of cavities of the type that are seen in the present photomicrograph, my suspicion is that these are etch pits caused by too long an etch. You can try progressively reducing the etching time until you arrive at a microstructure that shows the presence of carbides instead of pits. You can tell which is a pit and which is a precipitate after focusing and defocusing several times. At a magnification of approx. 1000X you have used, educated guess is the best option in my view.
Thank you dear Malur Srinivasan. your guidance and attention in my asked is great for me.
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