Simultaneously improved strength and elongation at cryogenic temperature in Ti-5Al-1V-1Sn-1Zr-0.8Mo alloy with a bimodal structure

The tensile properties and deformed microstructures of Ti-5Al-1V-1Sn-1Zr-0.8Mo (Ti5111) alloy with a bimodal structure under different deformation temperatures are investigated. As the deformation temperature decreases from 0 degrees C to -196 degrees C, the tensile strength, and elongation of Ti5111 increase simultaneously. The distinguishing characteristic of the deformed structure is the presence of {1012}1011 deformation twins (DTs) at -196 degrees C. These DTs can improve the tensile elongation by twinning-induced plasticity (TWIP), and make additional grains amenable for dislocation slip by changing the local microstructure orientation, promoting homogeneous deformation and contribute toward a higher elongation at -196 degrees C than that at 0 degrees C. The enhanced tensile strength at -196 degrees C is attributed to the coupling influence of the higher stress of dislocation slip at cryogenic temperature and the deformation twins-induced grain refinement.

Automated summary

The study investigated the tensile properties and deformed microstructures of a Ti5111 alloy with a bimodal structure under different deformation temperatures. The presence of deformation twins at -196 degrees C contributes to improved tensile elongation and higher tensile strength.