In this work, the Phillips PW 3020 X’Pert Diffractometer and PANalytical X’Pert Pro MPD X-ray Diffractometer were compared during in-situ monitoring of quenched microstructures to define the defect evolution of Inconel 718 additive manufacturing powder and quantify factors influencing measurement accuracy and precision. Dislocation density analysis based on X-ray Diffraction (XRD) measurement is sensitive to XRD peak broadening. The X-ray line profile is affected by the instrumental effects of the diffractometer, so quantifying and analyzing XRD instrument performance is important for accurate dislocation density analysis. Over the observed dislocation density range of ⋅1014 m-2 (2.58 - 3.93)⋅1014 m-2 the average measurement bias of the Phillips diffractometer was found to be -1.5490⋅10-3 Å while the precision was found to be 6.1000⋅10-5 Å. The average measurement bias of the PANalytical diffractometer was found to be -1.7633⋅10-4 Å while the precision was found to be 7.6917⋅10-5 Å.  The number of diffraction peaks utilized in dislocation density analysis was found to be a more significant factor than the instrumental differences. This work confirmed that differences in defect structure density can be observed across differently sized particles sourced from additive manufacturing powder.

Moderated by: Hideyuki Yasuda