Impact of hot isostatic pressing treatments on the mechanical performance of EBMed Ti-6Al-4V alloy

The present study compares the efficiency of three different Hot Isostatic Pressing (HIP) post-treatments in reducing the density of defects in Ti-6Al-4V alloy parts fabricated by the Electron Beam Melting process. The HIP treatments are the standard HIP (T = 920 degrees C, P = 1000 bars, t = 2 h), a High-Temperature HIP (T = 1050 degrees C, P = 1000 bars, t = 2 h), and a two-step HIP (held above the beta-transus, rapid quenching, and tempering) treatments. If it is observed that all three HIP treatments do seal internal porosity and increase the final density of the material, they are also shown to differ mainly in significant variations in morphology, porosity and hardness. It is also shown that the observed decrease in density is only partly linked to the decrease in porosity and mainly to the evolution of the chemical composition of the two phases constituting the Ti alloy through the HIP post-treatment as well as the quality of the crystalline structure.

Automated summary

The study compares the efficiency of three different Hot Isostatic Pressing (HIP) post-treatments in reducing defect density in Ti-6Al-4V alloy parts fabricated through Electron Beam Melting. The HIP treatments include standard HIP, High-Temperature HIP, and two-step HIP. Although all three treatments seal internal porosity and increase material density, they show significant variations in morphology, porosity, and hardness. The decrease in density is mainly attributed to the evolution of chemical composition and crystalline structure.