Effect of B addition on the microstructure, mechanical properties, and corrosion behavior of Ti-24Nb-4Zr-2Mn alloys

In the present study, (Ti, Nb)B reinforced Ti-Nb-Zr-Mn alloys were successfully fabricated through ball milling and spark plasma sintering (SPS) process with the addition of TiB₂. The microstructure, mechanical behavior, and corrosion resistance in simulated body fluid of the as-prepared alloys were systematically investigated. It was found that (Ti, Nb)B phases were in situ formed through reaction between the Ti-Nb-Zr-Mn matrix and TiB₂ particles, which significantly enhanced the mechanical strength of the alloys. As the TiB₂ with equivalent B mass fractions increased from 0 to 1 wt.%, the ultimate tensile strength of the alloys improved significantly from 945 ± 13 MPa to 1259 ± 8 MPa, while the elongation reduced sharply from 20.2 ± 2.2% to 1.9 ± 0.5%. Microhardness tests showed that the materials’ hardness increased as the fraction of the (Ti, Nb)B phase increased. Notably, the elastic modulus increased from 77.1 ± 0.5 GPa to 93.7 ± 0.7 GPa. Moreover, the appropriate introduction of B was beneficial to the corrosion resistance of the alloy in simulated body fluids.