Abstract:
A study was undertaken on the compressive high strain rate properties and deformation
behaviour of Direct Metal Laser-Sintered (DMLS) Ti6Al4V (ELI) parts in two separate forms: as-built
(AB) and stress relieved (SR). The high strain rate compression tests were carried out using a Split
Hopkinson Pressure Bar test system at ambient temperature. The average plastic strain rates attained
by the system were 400 s1 and 700 s1. Comparative analyses of the performance (flow stresses and
fracture strains) of AB and SR specimens were carried out based on the results obtained at these two
plastic strain rates. Microstructural analyses were performed to study the failure mechanisms of the
deformed specimens and fracture surfaces. Vickers microhardness test values were obtained before
and after high strain rate compression testing. The results obtained in both cases showed the strain
rate sensitivity of the stress-relieved samples to be higher in comparison to those of as-built ones,
at the same value of true strain.