Tuning microstructure and enhancing corrosion property of Ti-6Al-3Nb-2Zr-1Mo alloy through electron beam surface melting

Herein, we employ electron beam surface melting (EBSM) technology to process Ti-6Al-3Nb-2Zr-1Mo alloys and compare their microstructure and corrosion performance with wrought counterparts. The mechanism of microstructural evolution has been illustrated. The EBSM sample exhibits a better corrosion resistance than the wrought one, which can be ascribed to the formation of a relatively more stable passive film due to a higher fraction of phase boundaries induced by the fine α′-phase, and the alleviated heterogeneous distribution of compositions between α (α′)- and β-phases stemming from rapid cooling during EBSM process, further leading to the absence of strong galvanic-corrosion between different phases.