Dear all,
Three alloys cast in the same conditions and with equal dimensions were subjected to X-ray diffraction. Alloy 1 has dual-phase delta and gamma, but in alloys 2 and 3, with the increase of the chemical composition ratio, the fraction of the gamma phase decreases, but the delta phase increases. According to the attached image, the diffraction intensity of alloy 2 is significantly reduced compared to the other two alloys. With several times of surface exfoliation and repetition of diffraction, the results of alloy 2 also did not change.
Professors and researchers, please advise me on this problem, what factor can cause this unusual change and decrease in X-ray diffraction intensity?
Dear Amirreza Abdali ,
you may share a bit more details about your sample;
e.g.
a) powder or bulk type of sample?
b) use of spinning sample stage?
c) chemical composition of phases?
You may suffer from preferred orientation artifacts and x-ray attenuation when changing the chemical composition ratio;
but also when the chemical composition ratio changes you will have a different ratio of gamma and delta peak heights...(phase ratio changes):
and, at least, the large peak in (3) may be due to strong preferred orientation...
Best regards
G.M.
Dear Gerhard Martens ,
Thanks for your answer,
These stainless steel alloys were produced in a VAR Furnace with a gradual increase in the ratio of chromium equivalent to nickel equivalent, respectively from 1 to 3. It was attempted to prepare all three alloys under the same conditions. By changing the ratio of the chemical composition, must the gamma phase decrease, and the delta phase increase. However, the sharp change in the XRD peak intensity of alloy 2, compared to alloys 1 and 3, is unusual to me.
Dear Amirreza Abdali ,
thanks for feedback...
You expect a decrease in gamma phase... and that can be seen in the XRD pattern.
There is no 'sharp change in XRD peak intensity of alloy 2'! Please have a look at the intensity scale; all three scale are quite different. Plot all of them with the same scale...
In the case of (3) the sharp delta peak at around 105° is due to preferred orientation.
You should mill your samples to get rid of the preferred orientation issue.
Best regards
G.M.
Dear Gerhard Martens
Thanks so much for the helpful points,
Best Regards
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