As a leading manufacturer, TSM Technology Co. provides the engineering insights needed for mission-critical joints. For chemical passivity and extreme ductility, Grade 2 (ERTi-2) is your primary filler. For structural integrity and high-stress aerospace environments, Grade 5 (ERTi-5) is the industry benchmark. This guide breaks down the physics, metallurgy, and welding parameters for both.
Technical Specs
The performance of titanium welding wire is governed by its interstitial elements and alloying additions. Grade 2 is a Commercially Pure (CP) alpha-phase titanium, prized for its high corrosion resistance in oxidizing environments. Grade 5 (Ti-6Al-4V) is an alpha-beta alloy, engineered for maximum strength-to-weight ratio.At TSM, we strictly adhere to AWS A5.16 and ASTM B348 standards. Understanding these profiles is the first step in avoiding weld failure and ensuring long-term structural reliability.
Mechanical Property Comparison
| Grade 2 (Commercially Pure) | Grade 5 (Ti-6Al-4V Alloy) |
| CP Titanium Grade 2 offers the best balance of moderate strength and high ductility. | The 'Workhorse' alloy for aerospace, providing nearly 3x the strength of Grade 2. |
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Tensile Strength (UTS) 345 MPa min |
Tensile Strength (UTS) 895 MPa min |
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Yield Strength (0.2% Offset) 275 MPa min |
Yield Strength (0.2% Offset) 828 MPa min |
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Elongation (in 50mm) 20% min |
Elongation (in 50mm) 10% min |
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Elastic Modulus 103 GPa |
Elastic Modulus 114 GPa |
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Hardness 80 HRB typical |
Hardness 36 HRC typical |
Grade 2 (Commercially Pure)AWS A5.16 Chemical Composition (Filler Metal)
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ERTi-2 (Grade 2 Wire) Strictly controlled for high purity to ensure maximum weld puddle fluidity. |
ERTi-5 (Grade 5 Wire) Alloyed with Aluminum and Vanadium for superior high-temperature performance. |
| Titanium (Ti)：Balance | Titanium (Ti)：Balance |
| Iron (Fe)：0.20% max | Aluminum (Al)：5.5 - 6.75% |
| Oxygen (O)：0.08 - 0.16% | Vanadium (V)：3.5 - 4.5% |
| Carbon (C)：0.03% max | Iron (Fe)：0.25% max |
| Nitrogen (N)：0.015% max | Oxygen (O)：0.12 - 0.20% |
| Hydrogen (H)：0.008% max | Carbon (C)：0.05% max |
Titanium Welding Guide
Titanium is an extremely 'active' metal. At temperatures above 426°C (800°F), it reacts with atmospheric gases, leading to weld embrittlement. TSM engineers recommend strictly following the inert gas shielding protocols.
Shielding Strategy:
1.Primary Shield: Argon flow through the torch nozzle (99.999% purity).
2.Secondary (Trailing) Shield: Protects the cooling weld bead behind the torch.
3.Backing Gas: Protects the root of the weld from oxidation.
Parameters (TIG/GTAW)
| Material Thickness (mm) | Filler Wire Grade | Amperage (DCEN) | Gas Flow (L/min) | Nozzle Size |
| 1.5mm | ERTi-2 / ERTi-5 | 40 - 70A | 8 - 12 | #8 |
| 3.0mm | ERTi-2 / ERTi-5 | 90 - 130A | 12 - 15 | #10 |
| 6.0mm | ERTi-2 / ERTi-5 | 160 - 220A | 15 - 20 | #12 |
Grade 2 titanium welding wire is commercially pure titanium (CP Ti) with a minimum titanium content of 99.2%. Designated as ERTi-2 under AWS A5.16 and UNS R50120, it represents the most widely used unalloyed titanium filler metal in industrial applications. The "CP" designation indicates intentional control of interstitial elements (oxygen, nitrogen, carbon, hydrogen) to achieve specific performance characteristics.
Grade 5 Titanium Welding Wire
Grade 5 titanium welding wire is an alpha-beta alloy composed of 90% titanium, 6% aluminum, and 4% vanadium. Known as Ti-6Al-4V or ERTi-5 (AWS A5.16, UNS R56402), it's the most widely used titanium alloy globally, accounting for over 50% of total titanium consumption.
Applications
The decision between Grade 2 and Grade 5 wire is rarely about cost; it is about the environment of the finished part. Grade 2 is for Chemical passivity; Grade 5 is for Structural efficiency.
Chemical Processing
Use ERTi-2 for heat exchangers and reactors handling chlorides and organic acids.
Marine & Desalination
Grade 2 excels in seawater. Use ERTi-2 wire for long-term hull and pump longevity.
Aerospace & Defense
High-stress airframes and fasteners require ERTi-5 for its incredible fatigue resistance.
Automotive & Sports
Racing exhausts and mountain bike frames use Grade 5 for lightweight strength.
Frequently Asked Questions
We have compiled 5 of the most common technical questions our TSM support team receives regarding Grade 2 and Grade 5 filler selection.
Can I use ERTi-2 filler on Grade 5 base metal?
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Yes. This is a common practice to increase weld ductility. While the joint strength will be lower than Grade 5, the weld bead will be less prone to cracking.
What causes a titanium weld to turn blue?
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Blue coloration indicates oxygen contamination at high temperatures. Structural welds for aerospace or pressure vessels usually require a 'Silver' or 'Light Straw' color to pass inspection.
What is 'Extra Low Interstitial' (ELI) wire?
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Grade 23 (ELI) is a higher-purity version of Grade 5. It offers improved fracture toughness and is the standard for surgical implants.
How should I store TSM titanium wire?
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Keep wire in its original sealed packaging in a dry, temperature-controlled environment. Avoid contact with carbon steel or grease to prevent cross-contamination.
Why is ERTi-5 wire harder to weld than ERTi-2?
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The alloying elements (Al and V) in Grade 5 reduce the fluidity of the weld puddle and increase the risk of segregation if heat input is not strictly controlled.
