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)

Karasoglu M., Yasa E., Tan E., Kavak S., Söylemez E., KUŞHAN M. C.

KOVOVE MATERIALY-METALLIC MATERIALS, cilt.63, sa.5-6, ss.331-356, 2025 (SCI-Expanded, Scopus) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 63 Sayı: 5-6
  • Basım Tarihi: 2025
  • Doi Numarası: 10.31577/km.2025.5-6.331
  • Dergi Adı: KOVOVE MATERIALY-METALLIC MATERIALS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Central & Eastern European Academic Source (CEEAS)
  • Sayfa Sayıları: ss.331-356
  • Eskişehir Osmangazi Üniversitesi Adresli: Evet

Özet

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.