I have tried OES method to obtain composition of 2024 T4 multiple times. As per standard composition Cu should vary between 3.8-4.9 and Mg should vary between 1.2-1.9. The problem coming is that Mg stays like 1.24 but Cu comes out to be 3.50 . I have scratched the material to 80-320 grit size. Dont know what is my fault? the materials seems to be authentic.
Have someone faced such a problem in the past , if yes what method did you take to correct your mistake?? What steps did you take to improve composition reading? Did you change the method like EPMA?