Towards strength-ductility synergy in nanosheets strengthened titanium matrix composites through laser power bed fusion of MXene/Ti composite powder

Figures & data

Figure 1. (a) SEM image of as-received Ti₃C₂T_x MXene flakes, (b) high-magnification SEM image of a typical MXene flake and its preparation mechanism, (c) a bright-field (BF) TEM image showing the surface morphology of as-treated MXene, (d) and (e) BF TEM images showing the cross-sectional morphologies of few-layered and monolayered MXene nanosheets, respectively.

Figure 2. (a) and (b) SEM images of powder mixture prepared from pristine Ti powder and the CTAB-modified MXene nanosheets by ball-milling, (c) and (d) SEM images of CTAB-modified MXene-coated Ti powder prepared by solid-liquid fluidised bed.

Figure 3. SEM images of MXene/Ti composite powder fabricated by fluidised bed at different MXene concentrations: (a) 0.1 wt.%, (b) 0.3 wt.%, (c) 0.5 wt.% and (d) 1.0 wt.%.

Figure 4. SEM images of MXene/Ti composite powder fabricated by solid-liquid fluidised bed under a fixed MXene concentration of 0.5 wt.% but using different flow velocity: (a) 5sccm, (b) 3 sccm, (c) 1 sccm and (d) 0.5sccm.

Figure 5. Variation of MXene-content in composite powder as a function of fluidisation time.

Figure 6. (a) SEM image of the thermal-reduced MXene/Ti composite powder, and (b) laser reflectivity of pristine Ti powder and the MXene/Ti composite powder.

Figure 7. (a) Photographs of as-printed cubes of MXene/Ti composite powder under different parameters, and (b) the relative density of the as-printed cubes.

Table 1. Numbering of as-printed samples under different printing parameters.

Scanning speed (mm/s)	Laser power (W)
	100	150	200	250	300
500	S1	S2	S3	S4	S5
750	S6	S7	S8	S9	S10
1000	S11	S12	S13	S14	S15
1250	S16	S17	S18	S19	S20
1500	S21	S22	S23	S24	S25

Figure 8. SEM images of samples printed from MXene/Ti composite powder, showing the as-printed microstructure at different printing conditions.

Figure 9. High-magnification SEM images of as-printed samples, showing morphology and distribution of remained MXene nanosheets and their effect on the Ti matrix.

Figure 10. TEM studies of samples (a-c) S8 and (d-f) S17: (a, d, e) BF TEM images showing the morphology and distribution of remained MXene and the as-printed microstructure, (b) the corresponding DF TEM image of (a), (c) and (f) the morphology of extracted secondary phase from as-printed samples, and the insets in (c) and (f) are corresponding diffraction patterns and the composition of extracted phase, respectively.

Figure 11. (a) Tensile stress‒strain curves of as-printed MXene/Ti composites under different parameters, and (b) comparison of tensile properties among our printed composites with as-printed pure Ti sample and the ASTM standard cast Ti64 alloy.

Figure 12. SEM images of fracture surface of as-printed samples: (a) S8, (b) S13, (c) S17 and (d) S19.

Figure 13. Cross-sectional SEM fractograph of samples: (a and a’) S8 and (b and b’) S17.