Try Poulton's reagent.

Barker's reagent. There is problem  in finding the micro-structure for Al-Mg alloy with keller, poulton's and other reagents. For this alloy, barkers will be good.  

Hi, Sabir Farmani,

This link may be helpful for you to find right agent.

http://www.metallographic.com/Etchants/Aluminum%20etchants.htm

Good luck

Hi Sabir,current ASTM 407 standard

Current ASTM 407 standard can be useful for several types of based aluminum alloys.

Check the next link: 

Best regards

https://www.astm.org/Standards/E407.htm

Hi Saber. Anodizing with Barker's reagent worked best for my AA5083 sample (see image). Try it out for 1min and more duration if nothing can be observed under polarized light. Try using pure Al for cathode and magnetic stirrer for the process.

Good luck!

Try concentric Keller's reagent (50 ml  H2O, 25 ml HNO3, 15 ml HCl, 10 ml HF). Etching time varies between 30 sec to 5 mins. It will reveal the grain structure of any wrought aluminum.

Hello Saber,

You can try

50 mL methanol, 50 mL water, 2mL HF

Phillips' anodizing solution for pure Al and AI-Mg alloys.

Electrolytic, 30 V dc, 1-2 min, Al cathode. Grain contrast revealed under polarized light.

Or

82 ml of H2O, 15.5 ml of HNO3, 0.5 ml of HF and 3 gr of Cr2O3

Refer: Journal of Alloys and Compounds 712 (2017) 795-803

Thanks all