Of some possible interest for your query ― yet on conventional metallography: https://www.researchgate.net/post/What_is_a_good_etchant_for_AISI_321_stainless_steel

In order to prepare samples for EBSD you would need to either use a hand polishing procedure or an electro chemical etch. The surface quality required for EBSD is much higher than standard microstructural characterization techniques. You can follow a number of procedures from the literature. Usually hand polishing is done with SiC paper 320grit to 1200, yielding an even scratch free matte finish, followed by 9, 3, and 1 micron diamond solution (usually done for 15min each) resulting in a highly reflective mirror like finish and 0.3 micron colloidal silica vibro-polishing for 2-24 hours. The times of each step are highly contingent on the material. As far as electro polishing (done with something like Struers Lectropol) nitric acid or perchloric acid in methanol should do the trick.

If there are any surface defects in the sample the EBSD will pick that up and show a rainbow pattern and low confidence in those areas. You will know pretty quickly if you see strong kikuchi patterns or not. Overall EBSD sample prep can be difficult and requires a lot of trial and error. There are some tricks to improve results but the sample preparation is the most importatn part.

Thanks a lot sir

Remanent deformation is more detrimental to EBSD pattern quality than slight surface relief and good results can often be achieved by a light metallographic etch after careful metallographic preparation down to a 1um diamond polish. If you can find an etch that works its saves a lot of time compared to prolonged colloidal silica polishing. Good luck!

For EBSD studies, the final polishing must be done by using 3µm MD-Mol and 1µm MD-Nap and further polishing with MasterPrep Vibratory Polisher using colloidal silica suspension for 24h or more in order to create a strain free surface.