摘要 : Abstract The effects of heat treatment parameters on the mechanical properties of a selective laser melting Ti–6Al–4V alloy were studied using an L9 (34) type orthogonal test. Results showed that the solution temperature and aging... 展开 Abstract The effects of heat treatment parameters on the mechanical properties of a selective laser melting Ti–6Al–4V alloy were studied using an L9 (34) type orthogonal test. Results showed that the solution temperature and aging temperature were the most influential factors relative to the mechanical properties. The optimum heat treatment was then obtained as 920 °C/2?h/water quenching?+?550 °C/3?h/air cooling and the corresponding tensile strength was 1045.2?MPa and the elongation was 13.6%. Compared to a solution temperature of 850 °C, more fine secondary α phase (αS) and higher geometrically necessary dislocations (GND) density were obtained when solution temperature was 920 °C, which promoted the increased strength by increasing the interface strengthening effect of αS/β and the dislocation strengthening. However, the microstructure of the continuously coarsening αGB resulted in decreased elongation when the solution was at 920 °C. As the aging temperature increased from 550 to 650 °C, the GND density was reduced and the microstructures of primary α (αP), αS with various crystallographic orientations, lamellar α, and equiaxial αP were coarsened. Therefore, the elongation of the specimen aging at a higher aging temperature increased while the strength decreased.Graphical Abstract 收起