Influence Of Forging Process On The Organization And Properties Of Titanium Alloy Bars

In recent years, with the expansion of the market, China's titanium industry has developed significantly, and new titanium alloy grades have been developed and applied. At present, the most widely used titanium alloys at home and abroad are TC4 (Ti-6A-4V), Ti-6Al-2Sn-4Zr-2Mo and so on. However, the high price of titanium alloys and the difficulty of smelting and processing result in the high cost of titanium, which is 8-10 times more expensive than steel. In some cases, the price limits the application of titanium alloys.

The TC4 (Ti-6A-4V) alloy is a typical a+0 two-phase alloy. The alloy was developed in the United States in the 1950s and has excellent overall properties. It has excellent process plasticity and superplasticity. It is suitable for all kinds of pressure molding and is widely used in the aviation and aerospace industries. It can be used to manufacture various parts with working temperature below 400℃, accounting for more than half of the dosage of titanium alloys.In the late 1950s, China began to study and try to produce Ti-6Al-4V alloy.In 1970, it was named as TC4 alloy, which is one of the most mature alloys in production and application among the many titanium alloys imported and imitated by China. As Mo and V in titanium alloy are the same image elements but relatively stable, China's molybdenum resources than molybdenum and vanadium resources are abundant, the utilization potential is huge.

The experimental materials are BTi62 titanium alloy ingots melted three times in vacuum self-melting electric arc furnace. The 0 phase transition temperature of the ingot is 1000~1020℃. The ingots were forged in 2500T fast forging machine, 3150T water press and SXP fine forging machine. Finished bars of 027.5 mm were obtained.

TC4 (Ti-6Al-4V) alloy is mainly used for working temperature below 450°C. BTi62 titanium alloy is designed to replace V element with Mo element, and the performance of this alloy is comparable with TC4 (Ti-6A 4V). The current high-temperature tensile index for TC4 alloys in national standards and national military standards is 400°C. Therefore, in the study of BTi62, the 400°C high-temperature tensile properties were compared with those of the same specification TC4.