If you want a non-chemical route XRD line widths can give grain size from Debye-Scherre formula

Hi

I need a chemical attack,to check the sample by means of a confocal microscopy

Finally,

I was found the info in this link: http://www.cartech.com/news.aspx?id=578

A Guide to Etching Specialty Alloys for Microstructural Evaluation

I've used 20ml HCl + 4ml H2O2 (3%) and it works

Greetings

Hi

This etchant procedure tends to work well for most CoCr and CoNiCrMo superalloys.

6 mL H2O + 6g CuCl2 + 60 mL Hydrochloric (HCl)

If material contains significant cold work, try a cold etch (immersion) with agitation for 10 to 120 seconds (start low). Cold worked material will etch more quickly due to defect structure and stored energy.

If material reacts slowly, or material is annealed, you will almost certainly need to heat your sample to approximately 70-100C, then immerse in the etchant with agitation for several seconds (or more).

This method should give very nice grain boundary and twin relief.

Cheers!