PSI - Issue 43

Pavol Mikula et al. / Procedia Structural Integrity 43 (2023) 119–123 Author name / Structural Integrity Procedia 00 (2022) 000 – 000

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one – (b) which thanks to a high resolution, detects a small fraction of a precipitation phase. According to the paper of Čapek et al. (2021) , the peak shown in Fig. 4a corresponds to a mixture of matrix  phase with  ´and  ´´ phases. On the other hand, the main peak shown in Fig. 4b (the red line) corresponds to the matrix  and  ´ phase, while the small fraction which can be attributed to the  ´´ phase, is detected on the peak shoulder (the green line). Fig. 4c shows that in the case of wrought aged sample, together with the main  phase (red line), there is a considerable contribution

FWHM 1 = (0.040 ± 0.002) deg FWHM 2 = (0.178 ± 0.014) deg

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FWHM 1 = (0.049 ± 0.002) deg FWHM 2 = (0.049 ± 0.011) deg

FWHM = (0.073 ± 0.002) deg

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 A / deg

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of a mixture of  ´ and  ´´ phases ( the wide blue line). The difference in peak positions is about 0.05 o . When using the values of the lattice spacings from the thesis of Repper (2010) and a simple formula  A ≈ -  (2  S ) valid for large values of R A , our results correspond well to the ones obtained in the paper of Čapek et al. (2021) and K ü mmel et al. (2021). Then, the change of the lattice spacing of the sample can be determined from the relation   S = -(  d S / d 0,S ) tan  S . 4. Conclusion The feasibility of using the high-resolution three-axis diffractometer setting in some special studies exploiting analysis of the diffraction profile and its angular position (e.g. strain/stress analysis of plastically deformed samples, determination of phases having very close values of the lattice spacings) is presented. Due to its high resolution, this diffraction alternative can be utilized, namely, in the case of samples subjected to thermo-mechanical load, see Davydov et al. (2008), Macek et al. (1996), Hirschi et al. (1998). Of course, the presented high-resolution performance can be used for macro strain scanning, but due to the step-by-step analysis with the analyzer, the measurement would be time consuming and impractical as a result of a rather low detector signal. We hope that the presented neutron diffraction setting can offer an additional support to complement the information achieved by using the other conventional characterization methodologies, (see e.g. Repper (2010), Čapek et al. (2021) , Kümmel et al. (2021) ). Acknowledgements Measurements were carried out at the CANAM infrastructure of the NPI CAS Řež supported through MŠMT project No. LM2015056. The presented results were also supported in the frame of the following MŠMT projects: LM2015048 and the infrastructural one - "Experimental nuclear reactors LVR - 15 and LR - 0 " . We thank Ms. B. Michalcová for a significant help in the measurements and basic elaboration of the data. Fig. 4. Analyzer rocking curves for the Inconel 718 in the vicinity of the (111) reflection of the γ matrix phase for the wrought sample - (a), the SLM one – (b) and the wrought aged one – (c).