Quantitative comparison of laboratory-based diffraction contrast tomography (DCT) and serial-section three-dimensional electron backscatter diffraction (3D-EBSD) for microstructural characterization of pure Fe and a modified E309L stainless steel

This study presents a quantitative comparison between laboratory-based diffraction contrast tomography (LabDCT) and serial-section three-dimensional electron backscatter diffraction (3D-EBSD) for microstructural characterization of fully recrystallized pure Fe (BCC) and chill-cast modified E309L austenitic stainless steel (FCC). Using 3D-EBSD as a high-resolution laboratory reference, the performance of LabDCT is evaluated in reconstructing grain morphology, topology, and the five-degree-of-freedom (5DOF) crystallographic character of grain boundaries. LabDCT reproduces grain morphology, size distributions, and dominant crystallographic orientations in both materials, with discrepancies primarily associated with small surface-adjacent grains. In the cast E309L alloy, larger deviations are linked to residual strain and intragranular orientation gradients inherited from solidification, which reduce diffraction completeness and increase local reconstruction uncertainty. Despite these effects, global topology metrics, including face, triple-junction, and quadruple-point statistics, show comparable trends between the two techniques. LabDCT also captures the principal features of misorientation distributions, coincidence site lattice (CSL) networks, and grain boundary plane distributions (GBPDs). Both methods identified the dominant coherent-twin orientations: {211} Σ3 and {031}/{021} Σ5 in Fe, and {111} Σ3 with {111}/{110} Σ5 in modified E309L, whereas weaker vicinal facets are less distinctly resolved by LabDCT. Overall, this benchmarking study establishes LabDCT as a robust laboratory-scale method for volume-resolved grain mapping and dominant boundary-character analysis across microstructures of differing complexity, while clarifying the conditions under which its interpretations require careful consideration or complementary higher-resolution techniques. • Direct quantitative comparison between Lab-DCT and serial-section 3D-EBSD. • Strong agreement in grain morphology, topology, and crystallographic texture. • Minor deviations linked to unresolved fine grains and orientation smoothing. • DCT accurately reproduces 5-DOF grain boundary character across BCC and FCC.