Mechanical characterization and deformation behavior of β-stabilized Ti-Nb-Sn-Cr alloys

A serial of Ti-25 wt% Nb-(1, 3, 5) wt% Sn-(2, 4) wt% Cr alloys were designed with aim to obtain a single β phase matrix in the microstructure for high performance. The newly designed alloys were produced through cold crucible levitation melting to characterize the effect of Cr and Sn on the microstructure, phase constitution and mechanical properties of the titanium alloys. All the investigated alloys display a monolithic β phase microstructure and exhibit high maximum strength (∼5 GPa) as well as superior plasticity (∼80%, without failure even though the maximum load limit is reached at the load capacity of 100 kN). Deformation mechanism is anticipated on the basis of twins and slip band patterns obtained in the vicinity of micro-hardness indentation, B o ¯ - M d ¯ phase stability map and e / a ¯ - Δ r ¯ diagram. Moreover, shear band analyses on deformed samples are also conducted. Additionally, the evaluation of wear resistance indices (H/E and H3/Eeff2) are employed in the present work. Amongst all the investigated alloys, Ti-25Nb-1Sn-2Cr shows the lowest Young’s modulus (66 GPa) with the highest values of yield strength, hardness and wear resistance indices.