Tungsten electrodes are non-consumable welding electrodes used primarily in Gas Tungsten Arc Welding (GTAW / TIG) and Plasma Arc Welding (PAW). They generate a stable electric arc to melt the base metal without melting into the weld pool.
Composition & Alloying
| Electrode Type | Approx. Composition | Purpose |
|---|---|---|
| Pure Tungsten (Green) | ~99.5% W | Stable arc on AC welding |
| Thoriated Tungsten (Red/Yellow) | ~97–98% W + 1.7–2.2% ThO₂ | Improved arc start & current capacity |
| Ceriated Tungsten (Gray/Orange) | ~97–98% W + 1.8–2.2% CeO₂ | Excellent low-amperage arc stability |
| Lanthanated Tungsten (Gold/Blue) | ~97–98% W + 1.5–2.0% La₂O₃ | Versatile AC/DC performance |
| Zirconiated Tungsten (White/Brown) | ~98% W + 0.7–0.9% ZrO₂ | AC welding with stable balled tip |
| Rare Earth Mix | Various RE oxides | Enhanced overall performance |
Physical Properties
• Melting point: ~3422 °C (highest of all metals)
• Density: ~19.3 g/cm³
• Excellent electrical conductivity
• Extremely low vapor pressure at high temperature
Mechanical & Metallurgical Behavior
Tungsten exhibits very high tensile strength (>750 MPa) and stiffness (Young’s modulus ~400 GPa). At room temperature it is brittle and must be handled carefully. Oxide additions improve electron emission and arc stability rather than mechanical strength.
Key Characteristics
✔ Highly stable and focused arc
✔ Excellent electron emission
✔ Non-consumable electrode
✔ Minimal weld contamination
✔ Long service life
Manufacturing & Processing
Produced via powder metallurgy, pressing, and sintering to achieve a dense, uniform structure. Alloying oxides are blended before sintering to ensure consistent arc performance. Electrodes are ground to specific tip angles based on AC or DC welding requirements.
Available Sizes
Rod lengths typically range from 150 – 610 mm
Diameter range: ~0.5 mm to 8 mm
Color-coded ends for easy identification
Applications
Welding
TIG welding of stainless steel, carbon steel, aluminum, titanium,
nickel alloys, and copper alloys
Plasma Welding & Cutting
High-temperature, precision arc applications
Advantages
✔ Withstands extreme heat without melting
✔ Produces clean, high-quality welds
✔ Long electrode life
✔ Wide current range compatibility
✔ Reduced downtime
Limitations & Safety
⚠ Brittle — careful handling required
⚠ Thoriated electrodes require dust control during grinding
⚠ Proper preparation needed for optimal results
Why Choose Tungsten Electrodes?
Choose tungsten electrodes for precision welding where arc stability, durability, and weld cleanliness are critical. Selecting the correct alloy type significantly improves weld quality and efficiency.