Fe nanoparticles modified pure Ti alloy on microstructure evolution and fine crystallization mechanism fabricated by additive manufacturing

It has been confirmed that micro-alloying is the effective way to refine the grain size and elevate the properties of pure Ti alloy produced via additive manufacturing. The pure Ti, Ti -2Fe (wt.%) and Ti-4Fe (wt.%) alloys created via Laser Melting Deposition (LMD) are compared based on their grain size, orientation relationship, and mechanical properties. Ti -4Fe displays a significantly lower average grain size of 220 mm in comparison to pure Ti and Ti-2Fe alloys, with average size of 442.3 and 319.6 mm. The superior constitutional supercooling of the former is responsible for the decrease in grain size. The orientation of the a phase is found to be influenced by the solid solution of Fe, with greater Fe content resulting in a preference towards the (0 0 0 1) direction for growth. Furthermore, the in-clusion of Fe led to a noteworthy increase in both the yields strength, peaking at 798 MPa, and tensile strength, reaching 880 MPa. This enhancement is attributed to both the fine grain strengthening (54.4%) and the solid solution strengthening of Fe atoms (45.6%).(c) 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).