Microstructure, tensile properties and deformation behaviour of a promising bio-applicable new Ti35Zr15Nb25Ta25 medium entropy alloy (MEA)

Effects of Zr Addition on the Microstructural Evolution, Mechanical Properties, and Corrosion Behavior of Novel Biomedical Ti–Zr–Mo–Mn Alloys

“…Introducing solutes with a large atomic radius will induce severe lattice distortion due to the atomic radius mismatch, which is accordingly responsible for the unprecedented mechanical properties of the multiprincipal element alloys. , The atomic radius difference δ is an important physical parameter, which can be described as follows where c i is the concentration of element i , r̅ is the average atomic radius, and r i is the atomic radius of element i . Here, the value of δ provides a measurement for the lattice distortion and is directly related to the effect of solid-solution strengthening . In this work, the calculated δ values are 3.24, 4.05, and 4.29% for (TZ) 5:1 MM, (TZ) 2:1 MM, and (TZ) 1:1 MM, respectively, indicating the enhanced lattice-distortion effect caused by the addition of the Zr element.…”

“…Here, the value of δ provides a measurement for the lattice distortion and is directly related to the effect of solid-solution strengthening. 18 In this work, the calculated δ values are 3.24, 4.05, and 4.29% for (TZ) 5:1 MM, (TZ) 2:1 MM, and (TZ) 1:1 MM, respectively, indicating the enhanced latticedistortion effect caused by the addition of the Zr element. The change of the relative fraction of β and α phases versus Zr content can be further reflected by the metallographic images (in Figure 2).…”

A Review: Design from Beta Titanium Alloys to Medium-Entropy Alloys for Biomedical Applications

“…Figure 9a-c depict the relationships between the moduli and various thermodynamic parameters of published Bio-HEAs/MEAs [51,70,72,73,75,76,[78][79][80][81][82][83][84][85][86][87]. From Figure 9a, it can be seen that reducing the ∆S mix values of Bio-HEAs/MEAs effectively lowers the modulus, attributed to the design with non-equiatomic compositions resulting in a lower modulus (see "Section 4.2").…”

“…Mustafi et al [72], members of Nguyen's research team, then developed a Ti 35 -Zr 15 -Nb 25 -Ta 25 MEA with a fixed δ value of 4, aiming to achieve good mechanical properties and biocompatibility. However, the yield strength (842 MPa) and ductility (17%) of Ti 35 -Zr 15 -Nb 25 -Ta 25 were found to be lower than the previously developed Ti 45 -Zr 25 -Nb 25 -Ta 5 alloy [71].…”

“…On the other hand, the moduli of published Bio-HEAs/MEAs with various values of δ seem not show a clear trend. Figure 9d-f present the relationship between the moduli and various phase stability parameters of published Bio-HEAs/MEAs [51,70,72,73,75,76,[78][79][80][81][82][83][84][85][86][87]. As [Mo] eq and VEC decrease, a noticeable decrease can be observed in the alloy's elastic modulus.…”