Hello,

First of all, you need to be able to identify the correct phases exactly (https://www.youtube.com/watch?v=dASaENblC_4). If they are alloys, there may be substitutions in the lattice, so it may coincide with more than one phase that is crystallographically similar. Here, you will need to use some complementary characterization techniques to define it.

On the other hand, the ideal way to quantify phases in X-ray diffraction (XRD) is through Rietveld refinement. It is a complex task depending on the phases. I normally use FullProf.

It can also be done with Highscore Plus (Tutorial: https://www.youtube.com/watch?v=XTqx2iJ6NTI). There is also a simpler fitting method that, in my opinion, uses the direct derivation method (http://dx.doi.org/10.1107/S1600576716010451). However, it provides rather semi-quantitative values ​​(I don't know how reliable they are).

Thanks for the reply. Can you guide me with FullProf in finding the phase percentage analysis of the Inconel 718, which has multiple phases

Rietveld refinement of xrd pattern using fullprof is the most suitable method once you know each phases you have (using highscore, EVA...softwares) you can either determine exactly the lattice parameters of each phase and the mass fraction of each phase in the sample

The process is quite delicate at the beginning and needs more practice but it is a life saver

Here is the manual for a step by step refinement

https://psi.ch/sinq/dmc/ManualsEN/fullprof.pdf

Dear Alok Kumar :

Unfortunately, I can't help you through this medium. To learn how to use FullProf, you need to take a course or seek expert help in person.

The manual provided by Wissal Tout may be helpful.

P.S.: If you have the appropriate version of HighScore Plus, I've been told it makes Rietveld refinements easier to perform, although I haven't had the opportunity to use it.

Best regards.

AR

Hello Alok Kumar ,

I am not a metallurgist but QPA for Inconel 718 via RIR or Rietveld analysis should be possible in HighScore(Plus). Asking Copilot for the identifiable Phases in it turns up this table:

Phase Structure Type Composition Notes

γ FCC (Fm-3m) Ni-Cr-Fe matrix Dominant phase

γ′ Ordered FCC (L12) Ni3(Al,Ti) Strengthening, coherent

γ″ BCT (DO22) Ni3Nb Main strengthening phase

δ Orthorhombic (DOa) Ni3Nb Grain boundary phase

MC Carbides FCC (e.g., NbC, TiC) Nb, Ti, C Minor phase

So this should help to determine the correct matches/phases in the Database that you are using.

If the data is not a secret you can send me a Scan and I have a quick look.

Best regards,

Thomas

Thanks, Thomas Degen, for the reply. I am happy to share the scan data. Please find the attached raw file

Hello Alok Kumar

The 3 real peaks that you can see see in this Scan are explained already by one Fe/Ni FCC phase. You would need better data, with a way better Signal to Noise ratio for meaningful results (to more clearly see smaller peaks), especially for Rietveld QPA. At least you need 10000 Counts on the highest peak. But more would not hurt in this case. It looks like you used an Automatic Divergence Slit, how much of your sample did you irradiate?

Hello Thomas Degen

Thanks for the reply. I checked with the XRD technician — an Automatic Divergence Slit was used. Could you help me understand the possible reason for the weak peak intensity? My sample is polished, and its dimensions are 10 mm × 10 mm × 0.9 mm.

Hello Alok Kumar ,

You can simply increase the Signal to Noise ratio by measuring your sample longer, or adding up multiple measurements. Again, you should have at least 10000 CTS on the highest Peak. Just measure that sample 10 times as long and then come back. Note that there could be other issues, but that I cant oversee from here.

Hello Alok, when Thomas asked "It looks like you used an Automatic Divergence Slit, how much of your sample did you irradiate?" he was not asking for sample size (although that is good to know), rather the irradiated area. With a fixed divergence slit, the irradiated area will decrease throughout the scan since be beam is spread maximally at low incidence angle. With a automated divergence slit, the slit varies throughout the scan, gradually increasing its opening to keep the irradiated area constant. You want this to be set as large as possible within your instrument capabilities. So tell us about that.

And do repeat the scan for about 10x as long. The minor phase peak heights may be

Thanks for the correction w.s.l. Boyer, I will look into that part