Property Modification of Vacuum Consumption-Molten Ti-V-Cr Alloy by Y-Doping

The Y-doped Ti-22 V-10 Cr-2 Zn alloy,an advanced spacecraft engine material synthesized by vacuum self-consumption melting,was extruded and annealed.The influence of the Y-content on the microstructures and mechanical properties was investigated with scanning electron microscopy.The preliminary results show that the Y-doping had a major impact.Specifically, as the Y-content increased,the tensile-strength and cross-sectional area shrinkage ratio,measured at 23℃ and 600℃,changed in an increase-decrease mode;the elongation ratio significantly increased;and the yield-strength slowly decreased,resulting in improved plasticity.Doped at Y-0.1 wt%,the Ti-22 V-10 Cr-2 Zn-xY alloy displayed the best durability and creep behavior.The Y-doping considerably affected the microstructures,for example,formation of small grains at the Y-stripes edges,grain-size reduction and improvement of uniformity.We concluded that the Y-doping induced reconstruction of microstructures explains the modification of mechanical properties of Ti-V-Cr alloy.