Figure 9
The panel a contains four phase maps labelled a, b, c, and d. Panels a and b show the interface between N i T i and 316 L with a scale bar of 200 micrometres. Panels c and d show enlarged interface regions with scale bars of 20 micrometres. The maps identify austenite N i T i, martensite N i T i, and 316 L. Panel c labels austenite N i T i, martensite N i T i and 316 L, deformation, and interface. Panel d labels austenite N i T i and martensite N i T i and 316 L. The panel b shows diffraction patterns for N i T i powder and samples produced at 33.33 joules per cubic millimetre, 35.56 joules per cubic millimetre, 38.89 joules per cubic millimetre, 44.44 joules per cubic millimetre, 50 joules per cubic millimetre, and 66.67 joules per cubic millimetre. The horizontal axis is 2 theta from 10 to 110 degrees, and the vertical axis is intensity in arbitrary units. Diffraction peaks are marked for B 2 N i T i and B 19 prime N i T i phases. A highlighted peak is marked on the 33.33 joules per cubic millimetre pattern near 42 degrees.Phase and microstructural evolution across the LPBF-processed 316 L–NiTi interface (a) EBSD phase map of the cross-section of the 50 J/mm³ sample; (b) EBSD phase map of the cross-section of the 66.67 J/mm³ sample; (c) GROD map of a magnified region from (a) showing localized deformation in the austenite phase of NiTi; (d) Phase map of the magnified section in (b) showing a distinct mixture of the martensitic NiTi phase and iron-rich phases from the 316 L substrate close to the interface. Bulk XRD profiles supporting these phase variations at different energy densities are shown on the right (Ekoi et al., 2022)