Process understanding and optimization of nano-TiC powder surface functionalization for improved L-PBF printability of AA2017 alloy

Abstract Surface functionalization of aluminum powders with ceramic particles is an effective approach to mitigate solidification cracking during laser powder bed fusion (L-PBF) of high-strength Al–Cu alloys. Although such additions are known to promote grain refinement, their influence on alloy processability and on the L-PBF processing window remains insufficiently quantified. In this study, the effect of nano-TiC powder surface functionalization on the L-PBF behavior of the AA2017 alloy was investigated using porosity and cumulative crack length analysis. A Box–Behnken design of experiments, combined with analysis of variance (ANOVA) and supported by metallurgical knowledge, was employed to evaluate the influence of processing parameters. Both porosity and cumulative crack length decreased with reduced scanning speed and increased laser power, while hatch distance showed no significant effect. Compared to the unmodified AA2017 alloy, the TiC/AA2017 alloy consistently exhibited lower porosity and cumulative crack length across most processing conditions and an expanded processing window for solidification crack suppression. Statistical regression models enabled an optimized parameter set (P = 190 W, v = 100 mm/s, h = 120 μm) that produced AA2017 samples with low porosity (0.17 ± 0.06%) and crack density, and crack-free TiC/AA2017 samples with low porosity. Beyond improved processability, nano-TiC functionalization promoted microstructural refinement with columnar-to-equiaxed transition and resulted in enhanced tensile strength (366 ± 13 MPa) and ductility (14 ± 5%) without compromising hardness. Overall, nano-TiC powder surface functionalization provides a scalable route to expand the L-PBF processing window and improve the reliability of high-performance Al–Cu alloys.