TC4ELI titanium alloy is widely used in integral load carrying components of aircraft due to its excellent strength

ductility and damage tolerance. However

due to the different primary β grain morphology and microstructure of TC4ELI titanium alloy component manufactured by additive manufacturing

different heat treatment methods are often required from forgings. Therefore

to obtain a suitable heat treatment method for additive manufacturing TC4ELI

the microstructure of as-deposited TC4ELI titanium alloy fabricated by laser additive manufacturing and the effect of hightemperature annealing on the microstructure and mechanical properties of laser additive manufacturing TC4ELI titanium were studied. The results show that with the increase of annealing temperature in the dual-phase zone

the width of primary α phase increases

the content of primary α phase decreases

and the secondary α participates. After the single-phase zone annealing

TC4ELI titanium is still ultrafine basket-weave microstructure. The microhardness and yield strength of TC4ELI titanium alloy after annealing in the dual-phase zone decreases slightly

the tensile strength increases slightly

the ductility dose not change much

and the anisotropy dose not improve significantly. However

the strength increases slightly and the ductility decreases significantly after annealing in the single-phase zone. Different from the annealing of forging TC4ELI in the single-phase zone

the strength and ductility matching of additive manufacturing TC4ELI is better after annealing in the dual-phase zone.