A titanium alloy for spring parts, consisting of aluminum 2.0% ~ 4.0%, molybdenum 2.0% ~ 4.0%, vanadium 2.0% ~ 4.0%, chromium 2.0% ~ 4.0%, iron 2.5% ~ 4.0%, allowance of titanium and inevitable impurities. The invention also provides the preparation method of the titanium alloy as follows: 1. Raw materials are weighed according to the mass ratio and pressed into consumable electrodes, and ingot is obtained after three times of vacuum consumable arc melting; 2. The cast ingot for opening forging, and then after forming forging or forming rolling to get the bar blank; Three, the bar after solution and aging treatment, titanium alloy for spring parts. The invention is simple, low cost and suitable for large-scale industrial production. The titanium alloy used for spring parts of the invention has excellent mechanical properties; The spring prepared by the invention has a fatigue life ≥5×105 times, stable performance and easy to realize industrial production.
Compared with steel springs, titanium springs have the advantages of low elastic modulus and low density. By the mid-1980s, Also began using Ti-13-11-3 alloy springs on L-1011 aircraft, and the β -C titanium alloy (Ti-3Al-8V-6CR-4Mo-4Zr, Ti-38-6-44) became a candidate spring material. The performance of β -c alloy is comparable to that of TI-13-11-3, but the cost is greatly reduced. β -c titanium alloy is mainly used as hatch door balance spring, flight control spring, aircraft joystick spring, pedal reset spring and hydraulic system reset spring, etc. McDow uses about 300 Ti-13_LL_3 alloy springs and 150 β -c alloy springs on the MD-80 and MD-IL aircraft. European airbus α -330 and α -340 aircraft use β -c alloy springs with tensile strength between 1240MPa and 1450MPa, and American Boeing 777 aircraft also have β -c alloy springs. In the early 1980s, The United States began to pay attention to the application of titanium in the automobile manufacturing industry. At that time, Ford Motor Company did a lot of evaluation work on titanium suspension springs, valve springs, etc., but due to cost reasons, titanium parts have not entered the mass production models. In order to reduce the cost, Timet developed a low-cost β titanium alloy Timetal LCB by using low cost Mo-Fe intermediate alloy in the smelting process. Its nominal component is Ti_6.8Mo_4.5Fe_L.5α 1.
The invention provides a titanium alloy for spring parts with excellent mechanical properties. The tensile strength Rm≥1500MPa, yield strength Rpa2≥1400MPa, elongation A5≥ 8.0%, area shrinkage Z≥20%, dynamic elastic modulus EdS llOGPa at room temperature 23°C ±2°C. The spring made of titanium alloy with the spring has a fatigue life ≥5X IO5 times, stable performance, easy to achieve industrial production, can meet the technical requirements of aerospace, shipbuilding, automobile and other fields. In order to solve the above technical problems, the invention adopts a titanium alloy for spring parts.
