Effect of Heat Treatment on Corrosion Properties of Ti-6Al-4V Titanium Alloy Produced by Electron Powder Bed Fusion

Electron powder bed fusion (EPBF), as one of the common additive manufacturing techniques, has received increasing attention. EPBF-processed Ti-6Al-4V is widely used in biomedical and aerospace industries. However, titanium alloys prepared by EPBF have large pores and poor corrosion resistance. Heat treatment is a simple and non-polluting way to improve material properties. However, the effect of heat treatment on the corrosion resistance of EPBF-processed Ti-6Al-4V alloy has not been thoroughly researched. In this paper, Ti-6Al-4V samples processed by EPBF were treated with different heat treatment methods. All corrosion tests were performed in 3.5 wt.% NaCl solution at ambient temperature. HT800 has the highest content of β phase, and the smallest grain boundary density, and therefore has the best corrosion resistance. The corrosion current of HT800 is reduced from 0.109 µA/cm² unheated to 0.022 µA/cm², a reduction of 79.82%.