The titanium alloy is composed of the following mass percentages of elements: Al 4.0%~5.0%, Mo 5.6%~6.5%, V 2.5%~3.5%, Cr 1.5%~2.5%, Fe 1.5%~2.5%, the allowance for Ti is the inevitable impurity; The molybdenum equivalent is 13~16. Of the present invention provides high strength titanium alloy is relative to the high strength titanium alloy, reducing the price is higher amount of alloy element chromium and vanadium to add, do not add expensive alloying elements such as zirconium and niobium, also can make the preparation of the invention is high strength titanium alloy 1400MPa grade, and has more than 7.5% of break elongation, good strong plastic matching, The cost is lower than other titanium alloys of the same strength, which can be widely used in aerospace, military and civil fields, and significantly improve economic benefits.
Titanium alloy is widely used in aerospace, military weapons and equipment, civil chemical industry and other fields, especially in the aerospace field, because of its super high specific strength, good mechanical properties and corrosion resistance. Titanium alloy can greatly reduce the weight of the aircraft and aircraft, effectively expand the flight distance of the aircraft, so as to improve flight efficiency, so the proportion of titanium alloy in the aircraft is increasing generation by generation. However, with the development of aerospace industry, the upgrading of military weapons and equipment, as well as the energy conservation and emission reduction of chemical industries, higher performance requirements are put forward for titanium alloys. At present, most titanium alloys can reach the highest strength of 1300MPa, such as Ti5553, TB10, etc., and with the increase of alloy strength, the plasticity decreases significantly. In addition, the cost of titanium alloy for the civil field is relatively high. Although the comprehensive performance of titanium alloy exceeds that of steel in some specific service environments, the red line of cost also limits the further application of titanium alloy. High strength titanium alloys in prior art are shown in Table 1.
A 1400MPa grade low cost high strength titanium alloy is available. The high strength titanium alloy is relative to the high strength titanium alloy, reducing the price is higher amount of alloy element Cr and V to add, do not add expensive alloying elements such as Zr and Nb, through the control of the high strength titanium alloy components to the tensile strength of high strength titanium alloy of the preparation of the invention is more than 1400 mpa, break elongation is not less than 7.5%, It has good strong plastic matching and the cost is lower than other titanium alloys of the same strength.
A 1400MPa grade low cost high strength titanium alloy is characterized in that the tensile strength of the titanium alloy after heat treatment is greater than 1400MPa, and the elongation after fracture is greater than 7.5%; The heat treatment process is: heating titanium alloy to β phase change point temperature below 30℃~50℃ for solution treatment, and then heating to 500℃~530℃ after holding for 4h aging treatment, and then air cooling to room temperature. This invention by controlling the parameters of solid solution treatment, keep the right amount of primary alpha phase in order to improve the plasticity of titanium alloy, the present invention by aging treatment, high strength titanium alloy large secondary alpha phase in the rapid precipitation, significantly improve the strength of titanium alloy, by controlling the time of aging treatment, ensure the high strength titanium alloy and peaked at 4 h.
