10th International Conference on Surface Engineering (ICSE 2026)

The aluminum/titanium (Al/Ti) couple is a typical “limited mutual solubility heterogeneous metal” system, in which fusion-based manufacturing often leads to brittle intermetallic compounds and cracks. This study systematically investigates the microstructure and mechanical properties of Ti6Al4V deposited on 6061Al substrates via laser-assisted cold spray (LACS). X-ray diffraction (XRD) results confirm that the process maintains solid-state deposition characteristics, with only the α-Ti phase detected, indicating no detectable Al/Ti intermetallic compounds by XRD across all conditions. Laser assistance significantly enhanced deposition layer densification; at 600 W, the porosity decreased from 11.81% to 0.41%. Electron backscatter diffraction and transmission electron microscopy (TEM) characterizations revealed that the LACS process triggered intense dynamic recrystallization, refining the average grain size from 1.906 μm to 0.813 μm. High-resolution TEM analysis further identified a nanoscale grain gradient and elemental transition zone layer at the bonding interface, demonstrating the formation of a compositionally graded interfacial region accompanied by mechanical interlocking and localized elemental redistribution. Performance tests showed that increasing the laser power increased the microhardness to 388.1 HV0.2. Compared to cold spraying, the LACS-600 W samples achieved a 40% increase in ultimate tensile strength (206.58 MPa) and a 100% improvement in elongation (2.17%). The results indicate that LACS provides a high-performance solid-state additive manufacturing solution for Ti6Al4V/6061Al heterogeneous structures through the synergistic effects of laser-induced thermal accumulation and particle tamping densification.

Ti6Al4V/6061Al; LACS; Solid-state deposition; Dynamic recrystallization; Metallurgical bonding; Mechanical properties