Improved understanding of the interactions between solutes and the austenite/ferrite interface can benefit modeling of ferrite growth during austenite decomposition, as the transformation kinetic is significantly affected by solutes that influence interface mobility. Solute-interface interactions dominate solute segregation at the interface in binary systems, but in multi-component alloys, solute–solute interactions may also affect segregation. In this study, interface segregation in Fe–Mn–N is examined and compared with Fe–Mn–C, to reveal the extent to which C affects the segregation of Mn. Atom probe tomography (APT) is well-suited to analyze solute concentrations across the interface, as this technique combines high spatial resolution and compositional sensitivity. Measurements of Mn show that segregation is only observed for Fe–Mn–C. This demonstrates that Mn segregation is primarily driven by an affinity for C, which also segregates to the interface. However, the measurement of N in steels by APT may be affected by a variety of experimental factors. Therefore, in verifying the Fe–Mn–N result, systematic examination is conducted on the influence of pulsing method (voltage versus laser), sample preparation (ion milling versus electropolishing), and vacuum storage on the measured N concentration. Both laser pulsing and focused ion beam sample preparation are observed to decrease the apparent N concentration.

The aim of the present work is to develop a materials selection strategy for biomedical Ti alloys by combining Ashby's method with a recently published dataset. The selection process concerns mechanical properties such as yield strength, elastic modulus, deformation at rupture, and the cost of the material. Outputs of the selection process point to alloys from both Ti‐Nb and Ti‐Mo systems as viable candidates for joint replacement materials. Additionally, this work discusses the crucial role of certain alloying elements in obtaining high elastic admissible strains, that is, a high yield strength‐to‐modulus ratio. Adding solutes such as Ta, Zr, Sn, Fe, and O is vital to stabilizing the β phase, suppressing the ω phase and increasing mechanical strength. Considering the minimum requirements of a 400 MPa yield strength, and 10% elongation at rupture, the best alloys identified via a multi‐objective optimization approach are Ti‐4.6Mo‐3.3Sn‐1.0Fe‐0.4O, Ti‐22.1Nb‐5Zr‐1.0Fe, and Ti‐20.3Nb‐4.7Ta‐2.5Sn (at%). These compositions present elastic moduli lower than 55 GPa, with an optimal trade‐off between a high elastic admissible strain and low cost. Updated property maps and analyses of conflicting properties are provided to support the conclusions.