Impact of heat treatment cycles on work hardening characteristics in selective laser melted Ti6Al4V ELI alloy

The present study investigates the influence of heat treatment cycles on the work hardening behaviour of a selective laser-melted (SLM) Ti6Al4V ELI alloy. To modify the microstructure and assess its impact on work hardening behaviour, the SLM Ti6Al4V ELI alloy is subjected to a series of heat treatment cycles, including solution treatment, quenching, and ageing. The microstructural evolution is characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). Tensile tests are conducted to investigate the work hardening behaviour, including yield strength, ultimate tensile strength, and strain hardening. The findings show that heat treatment cycles have a significant impact on the microstructure and work hardening behavior of the SLM Ti6Al4V ELI alloy. Solution treatment and quenching produce a refined α' martensitic structure by homogenizing the microstructure and dissolving the secondary phases. Subsequent ageing treatments induce the precipitation of secondary phases, such as α and β phases, within the α' martensite matrix.