The technology of tungsten-arc welding of TC6 titanium alloy
TC6 titanium alloy belongs to α + β two-phase alloy, which can be strengthened by quenching and aging, and can be adapted to various welding methods. If the tungsten argon arc welding method is adopted, the microstructure and plasticity of the joint must be stable by annealing after welding. It can work on the blade, ring and other parts of the aircraft and engine at 400 ℃ 450 ℃. TC6 titanium alloy has excellent hot working properties, good plasticity, low deformation resistance and good welding process. Whether it is tungsten argon arc welding or electron beam welding, the joint strength is not obviously reduced, but the plasticity and toughness are significantly reduced. In other words, this disadvantage is a difficult problem in the welding field. The titanium alloy of TC6 with thickness of 5.5mm usually adopts I-shaped or U-shaped groove, which is welded through at one time, while the U-shaped groove should be completed by 3 welds. The welding parts and wires should be cleaned before welding. The automatic tungsten argon arc welding machine should have good external characteristics of power supply and arc penetration. The starting tool and local protection device of the welding machine can control the welding deformation and the oxidation prevention of the joint area. The manual tungsten argon arc welding is carried out after filling argon in the vacuum box. When the pressure in the box is less than 0.133Pa, the argon of 0.1MPa is rushed into the argon gas of 0.1MPa. After welding, the cooling rate of 800 ≤ 810 ℃, 2h (vacuum degree is 0.002Pa), EC (810 ≤ 650C is about 1 ℃ / s).
