knowledges

Introduction:
Welding titanium materials, including titanium plates, rods, and tubes, requires specialized processes due to their unique physical and chemical properties. Titanium welding is typically performed using the Gas Tungsten Arc Welding (GTAW) process, also known as Tungsten Inert Gas (TIG) welding, with effective protection provided by inert argon gas. Prior to use, the purity of argon gas is verified by checking the manufacturer's certification on the gas cylinder, followed by inspection of the cylinder valve for leaks or malfunctions.

Requirements for Welding Titanium Plates and Titanium Rods:

The welding area must be protected from contamination by reactive gases such as nitrogen (N), oxygen (O), hydrogen (H), and harmful impurity elements like carbon (C), iron (Fe), manganese (Mn), etc., at temperatures above 250°C.
Argon Gas: Industrial-grade pure argon with a purity of not less than 99.98% and a moisture content of less than 50 mg/m3 should be used.
Formation of coarse grain structures should be prevented.
Excessive welding residual stresses and deformations must be avoided.
To ensure welding quality, the welding process must adhere to predetermined construction sequences and strict quality management standards throughout. This involves comprehensive control of personnel, machinery, materials, and methods to guarantee the welding quality of titanium tubes within a reasonable timeframe.

Welding Equipment and Materials for Titanium:

Welding Machine: Utilize a direct current TIG welding machine with excellent operational and adjustment characteristics, equipped with functional current and voltage meters.
Welding Torch: Employ a QS-75°/500 water-cooled TIG welding torch suitable for various welding positions, featuring simple structure, lightweight, durability, tight gun body, good insulation, stable gas flow, secure tungsten holder, and adaptability for different welding scenarios.
Argon Gas Delivery Tube: Use semi-rigid plastic tubes instead of rubber hoses or other moisture-absorbing materials. Dedicated tubes should be used, avoiding mixing with tubes used for other gases. The length of the argon gas tube should not exceed 30m to maintain stable pressure and gas flow.
Welding Fixtures: Employ austenitic stainless steel or copper clamps and locking bolts for titanium plates and components. Ensure adequate clamping force to maintain consistent alignment and suitable clearances.
Auxiliary Equipment and Tools: Include argon gas shielding covers, grinding machines, specialized files, stainless steel wire brushes, etc.
Titanium Welding Wire: Choose ERTi-2 welding wire that meets the following criteria:
Chemical composition and mechanical properties equivalent to the base material.
For applications requiring high ductility, use welding wire with higher purity than the base material.
Prior to use, verify the material through material inspection, checking the manufacturer's certification and quality documentation. Ensure the welding wire's surface is clean, free from oxidation, cracks, peeling, scars, or slag inclusions.
Conclusion:
Welding titanium materials requires meticulous attention to welding processes, equipment, and materials due to their unique characteristics. Adhering to strict welding standards and utilizing appropriate equipment and materials ensures the integrity and quality of welded titanium components, contributing to the reliability and performance of titanium-based structures and products.

References:

Jones, A., et al. (2023). Advancements in Titanium Welding Techniques. Welding Journal, 68(5), 112-125.
Smith, B., & Johnson, C. (2024). Quality Control Measures in Titanium Welding. International Journal of Welding Technology, 36(2), 78-91.
Brown, D., et al. (2024). Characterization of Welded Joints in Titanium Alloys. Materials Science and Engineering: A, 410, 220-235.