Abstract
This study investigates the effects of heat treatments and hot isostatic pressing (HIP) on the microstructure and mechanical behavior of Ti-6Al-4V parts manufactured by powder bed fusion using electron beam . Solution treatment at 950 °C followed by aging at 500−600 °C did not alter porosity levels. Aging increased the α-phase ratio and compensated for the strength reduction induced by ST. All HIP cycles significantly reduced pore size and pore count, with the 800 °C/200 MPa cycle yielding the highest average 99.86 % relative density and resulting in a maximum Yield strength of 948 MPa and a maximum ultimate tensile strength of 1013 MPa. 800 °C/200 MPa HIP cycle increased ductility while maintaining strength due to limited α-lath coarsening. Super-transus HIP at 1050 °C /100 MPa cycle transformed columnar β grains into equiaxed structures, causing significant α-lath coarsening, mechanical strength loss, and increased anisotropy. These findings emphasize the need to optimize post-processing to balance porosity elimination, microstructural refinement, and mechanical performance in Ti-6Al-4V components.

Key words
additive manufacturing, Powder Bed Fusion Using Electron Beam (PBF-EB), Ti-6Al-4V, heat treatment, hot isostatic pressing

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