Three-Dimensional Characterization of Selective Laser Melted Graphene Oxide-Reinforced Ti-48Al-2Cr-2Nb Alloy

Abstract

The influence of graphene oxide (GO) on selective laser melting (SLM) of Ti-48Al-2Cr-2Nb (at.%, Ti-4822) has been investigated using three-dimensional (3D) focused ion beam-scanning electron microscopy (FIB-SEM) tomography. The reconstructed 3D images from FIB-SEM tomography reveal the micro-/nano-features in the SLMed Ti-4822, including the dual-phase (α2 + γ) cellular structure and various types of defects. With the addition of 0.3 wt.% GO, the formed α2 cells are significantly refined, the γ phase network becomes thinner and more tightly packed, and the volume fraction of γ phase increases while that of α2 decreases. In addition, micro-cracks and nano-pores are observed in the SLMed Ti-4822, while only nano-pores with dramatically reduced size and number density are characterized in the SLMed Ti-4822 with GO. Our 3D characterization results have provided experimental evidence indicating that the addition of GO can improve the manufacturability of SLM of Ti-4822.