Microstructure, mechanical properties and corrosion resistance of a zirconium alloy fabricated by electron beam freeform fabrication

In this study, a zirconium (Zr) alloys was prepared by electron beam freeform fabrication (EBF³) technology. The microstructural characteristics, mechanical properties, and corrosion resistance properties of the as-deposited (AD) sample were systematically investigated. The results showed the AD sample was mainly composed of α phases, exhibiting the characteristics of coarse laths and preferred orientation. The ultimate strength (UTS), yield strength (YS), and the elongation of the AD sample were 442 MPa, 405 MPa, and 16.9 %, respectively. The average microhardness of the AD sample was 163 HV_0.2. Compared to the rolled (RO) substrate, the AD sample exhibited a decrease in the mechanical properties due to the formation of α laths. However, the AD sample exhibited better electrochemical corrosion resistance. The breakdown potential of the AD sample was 1.16 V, which was much higher than that of the RO sample (0.65 V). In addition, the oxidation rate of the AD sample in deionized water at 360 °C/18.6 MPa was comparable to that of the RO sample. This study suggests that the EBF³ technology is a viable method for fabricating Zr alloy parts.