Figure 4 | Scientific Reports

Figure 4

From: Superior Strength and Multiple Strengthening Mechanisms in Nanocrystalline TWIP Steel

Figure 4

C segregation to grain boundaries in HT-125 sample. (a) Bright-field TEM image and correlative APT results of C (red) obtained from the same tip. Red arrows and dotted lines mark grain boundaries visible in both TEM micrograph and 3D map. (b) 3D C atom map and corresponding 2D contour map for visual correlation with the APT map of segregation to four different grain boundaries. (c) 1D compositional profiles across matrix-boundary interfaces highlighted in the atom map reveal that not all grain boundaries contain the same chemical composition of C. (d) The sectional Mn (cyan) and C (red) distributions (measured volume = 50 nm X 50 nm X 150 nm). (e) 2D contour map of Mn that is superimposed to C atoms near the line dislocation (the magnified area is marked as a solid line; measured area = 8 × 16 nm2; red: high-quantity of Mn, blue: low-quantity of Mn). (f) 1D compositional profiles show both Mn and C are segregated at the line dislocation.