Influence of heat treatments and hot isostatic processes (HIP) on microstructure and mechanical behavior of Ti-6Al-4V alloy produced by Powder Bed Fusion Using Electron Beam (PBF-EB)
KOVOVE MATERIALY-METALLIC MATERIALS, vol.63, no.5-6, pp.331-356, 2025 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 63 Issue: 5-6
- Publication Date: 2025
- Doi Number: 10.31577/km.2025.5-6.331
- Journal Name: KOVOVE MATERIALY-METALLIC MATERIALS
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Central & Eastern European Academic Source (CEEAS)
- Page Numbers: pp.331-356
- Eskisehir Osmangazi University Affiliated: Yes
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 electron-beam powder bed fusion. Solution treatment at 950 degrees C, followed by aging at 500-600 degrees C, did not alter porosity. Aging increased the alpha-phase ratio and compensated for the strength reduction induced by ST. All HIP cycles significantly reduced pore size and pore count, with the 800 degrees C/200 MPa cycle yielding the highest average relative density of 99.86 %, resulting in a maximum yield strength of 948 MPa and a maximum ultimate tensile strength of 1013 MPa. An 800 degrees C/200 MPa HIP cycle increased ductility while maintaining strength, owing to limited alpha-lath coarsening. Super-transus HIP at 1050 degrees C/100 MPa transformed columnar beta grains into equiaxed structures, causing significant alpha-lath coarsening, a loss of mechanical strength, 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.