Simultaneously achieving superior strength and ductility at elevated temperature in laser powder bed fused Ti₂AlC MAX phase reinforced titanium matrix composites

Nanoparticle reinforcement via additive manufacturing presents a promising strategy to overcome the strength-ductility trade-off in titanium matrix composites (TMCs). Herein, we report the fabrication of Ti60 matrix composites reinforced with coherent Ti₂AlC MAX phase nanoparticles using laser powder bed fusion (LPBF). The LPBF-processed composites exhibit an exceptional combination of ultra-high tensile strength (872 MPa) and ductility (21 % elongation) at 600 °C, surpassing the Ti60 matrix alloy by 37 % in strength and 90 % in ductility. Microstructural characterization reveals that rapid solidification enables uniform dispersion of coherent Ti₂AlC nanoparticles along α lamellae boundaries, significantly refining the microstructure and increasing dislocation density. Quantitative analysis identifies grain refinement (40 % contribution) and dislocation strengthening (25 % contribution) as the dominant high-temperature strengthening mechanisms. The high-temperature enhanced ductility is attributed to the activation of multiple slip systems and dynamic recrystallization facilitated by high-density dislocations. This work demonstrates the potential of LPBF to synthesize coherent nanoparticle-reinforced TMCs with superior high-temperature mechanical properties.