A Low Modulus and High Strength Dual‐Phase Ti–Ta Alloy Manufactured by Laser Powder Bed Fusion

Ti alloys have emerged as promising candidates for biomedical implants owing to the favorable biocompatibility and corrosion resistance. Nevertheless, the inadaptability of elastic modulus between Ti‐based implants and human bones would trigger stress‐shielding effect, thus causing implant loosening or failure. In this study, α + β dual‐phase structure was in situ constructed in Ti–Ta alloys by manipulating LPBF process. The as‐printed Ti–Ta alloys were fabricated using optimized process parameters, hence exhibiting satisfactory manufacturing quality. This was because moderate laser power promoted Marangoni convection flow and thereby enabled the melt to fill gaps between adjacent laser tracks, while relatively low scanning speeds refrained Plateau–Rayleigh instability and further facilitated the formation of continuous molten pool. Furthermore, extremely high temperature gradient and transient solidification nature of LPBF suppressed the β → α transformation, further constructing α + β dual‐phase structure which contributed to a low modulus of 74.5 GPa. Meanwhile, dislocation pile‐ups, moderate sliding and localized rotation in grains contributed to enhanced strength (1143.4 MPa) without sacrificing ductility (10.6%) in Ti–Ta alloys. Overall, this study not only provides a maneuverable paradigm to manufacture dual‐phase Ti alloys with low modulus and high strength but also sheds light on developing and extending cutting‐edge implant applications.