Hydrogen trapping in additive manufactured Ti-6Al-4V alloy

Environmental degradation of Ti?6Al?4V alloy in the presence of hydrogen strongly depends on the interactions between hydrogen atoms and various microstructural defects. Thus, the initial microstructure of Ti?6Al?4V influences its performance in the presence of hydrogen. In this study, we compared hydrogen interactions and desorption characteristics of Ti?6Al?4V alloy prepared by selective laser melting (SLM) and electron beam melting (EBM). It was found that the processing has a strong influence on the susceptibility to hydrogen embrittlement (HE). The degradation of SLM Ti?6Al?4V in hydrogen containing environment will probably occur through hydride formation and cleavage mechanism. On the other hand, Ti?6Al?4V prepared by EBM is more likely to degrade through hydrogen enhanced localized plasticity (HELP) mechanism.

Automated summary

This study found that the susceptibility to hydrogen embrittlement (HE) differs significantly between Ti?6Al?4V alloys prepared by selective laser melting (SLM) and electron beam melting (EBM). The degradation of SLM Ti?6Al?4V in a hydrogen containing environment is likely to occur through hydride formation and cleavage mechanism, while Ti?6Al?4V prepared by EBM is more likely to degrade through hydrogen enhanced localized plasticity (HELP) mechanism.