Titanium alloys, with their High specific strength 30%  Its outstanding corrosion resistance ensures that it consistently remains a core material in fields such as aerospace, marine engineering, and medical devices. However, titanium... Its strong chemical reactivity above 400℃ makes welding a technical challenge—just a 0.01% increase in oxygen content can lead to a 20% drop in impact toughness. Based on the ASTM, ISO, and GB national standards systems, this article dissects the key technological secrets behind titanium alloy welding.

One, Choose the right welding method, and you’ll achieve twice the result with half the effort.

1. List of applicability for mainstream welding methods

No Too Recommended usage method : Shielded metal arc welding (the flux coating can easily introduce impurities), CO₂ shielded welding (oxidation rate exceeding 0.5%), gas welding (significant increase in hydrogen content in the weld).

2. Requirements for welding materials

• Protective gas : Must be adopted 99.99% Pure argon ( 4N Level), dew point ≤ -40℃ , total impurity content < 0.001% ( ISO 14175 ), nozzle flow rate 15-25L/min Back protection 5-10L/min。

• Welding wire matching ： TA1 Base material matching TA1 Welding wire (principle of equivalence); can be used when pursuing ductility. TA2 Wire welding TA5 (Downgrade matching), medical-grade Ti-6Al-4V ELI Should be used ELI Grade welding wire.

II. Adjust the parameters for more stable welding.

1. Recommended range for key parameters

• Tungsten Electrode Selection Cerium-tungsten electrode ( Ce-TIG ) The burn-off rate is much lower than that of pure tungsten. 30% , diameter 1-3mm , ground to a finish at the ends 30-45° Conical ( AWS A5.1 Standard).

• Bevel Design : Single V Bevel groove 70-80° For conventional selection, 60° The bevel will increase hydrogen absorption. 20% , leading to a decrease in impact toughness. 15% ; The thickness of the blunt edge is controlled within 0.5-1.0mm。

• Hot-affected zone control Temperature recommendation < 250℃ Otherwise, the oxide layer thickness is likely to exceed the limit. 5 μm The critical value needs to be monitored in real time using an infrared thermal imager.

2. Building a Multi-Layer Protection System

• The drag cover must extend over the back side of the weld seam. 300mm Area, ensure cooling to 350℃ The following;

• Argon pressure inside the tube during titanium tube welding 0.01–0.03 MPa Helping to achieve oxidation-free across the entire region.

Three, Assess welding quality and address common issues.

1. Assess quality by the weld seam color. ( GB/T 14976)

2.  Common Solution to the defect

Four, New Advances in Laser Welding of Titanium Alloys

Laser welding has become a research hotspot for titanium alloy welding due to its advantages of high energy density and a small heat-affected zone.

• The high-speed welding speed for thin plates can reach 3.6 m/min The process window is wider than that for low-speed welding.

• Pre-laid powder narrow-gap laser welding helps reduce porosity in thick plates and improves weld penetration stability. 40%；

• Laser - TIG Combined welding can increase the penetration depth. 2 Twice as much, reduced energy consumption 30%。

References

[1] Titanium Valley Trading Network. An In-Depth Guide to Titanium Alloy Welding Technology: Process Selection, Parameter Optimization, and Quality Control [EB/OL]. 2025-07-05.

[2] Baoji Kehui Titanium Industry. Mechanism of Interaction Between High-Energy Beams and Materials: Formation Mechanism of Defects in Laser Welding of Titanium Alloys [EB/OL]. 2025-09-10.

[3] Morrow. Analysis of Titanium Alloy Welding Technology: A Comprehensive Guide to Process Selection, Parameter Optimization, and Quality Control [EB/OL]. 2025-07-28.

[4] Laser Manufacturing Network. Research Status and Prospects of Laser Welding of Titanium Alloys [EB/OL]. 2025-11-14.

[5] GB/T 3375-2015, Procedure for Welding Process Qualification [S].

[6] ISO 14175:2019, Welding consumables—Wire electrodes, wires, rods and deposits for gas-shielded arc welding of non-alloy and fine grain steels[S].