This paper is concert about the mechanical property of high strength and high toughness titanium alloy BTi-6554 (Ti-6Cr-5Mo-5V-4Al) bars. The results show that: in β-phase zone solid solution + aging treatment condition, the strength and fracture toughness of the alloy at room temperature can reach a higher level while inα+β)-phase solution + aging treatment condition, the plastic property is relatively high. Compared with Ti-1023 and VT22 alloy bars produced by the similar processing procedure, the alloy shows improved properties combined in strength and toughness. BTi-6554 is a new type of titanium alloy with high structural efficiency, and has a good prospect for commercial and application.

The effect of Aluminum equivalent and Molybdenum equivalent on the strength and fracture toughness of titanium alloys was studied in this paper. The result shows that the tensile strength of the alloy increases with increasing of aluminum equivalent and molybdenum equivalent and the fracture toughness decreases gradually, the effect of aluminum equivalent is comparatively more conspicuous. A suitable value range of aluminum equivalent and molybdenum equivalent of high strength and high toughness titanium alloys are obtained from the analysis, based on this, a new type of high strength and high toughness titanium alloy BTi-6554 (Ti-4Al-5Mo-5V-6Cr) was developed, which has good combination of strength and fracture toughness and has the characteristics of high strength and high toughness.