New beta-type Ti-Fe-Sn-Nb alloys with superior mechanical strength

Ti-Fe-Sn-Nb alloys comprised of single β-Ti phase were developed showing excellent mechanical strength and superior plasticity. The alloys exhibited increased yield strength as a function of Fe content, where the Ti80Fe14Sn3Nb3 alloy presented the highest yield stress (1.88 GPa) comparable to that of Ti-based nanocrystalline alloys. Moreover, a significant strain-hardening (520 MPa) was achieved along with the plastic deformation. The excellent mechanical strength was enhanced by the supersaturated β-Ti and the high density of lattice defects that restrict the dislocation motion.