Which statement is true about aluminum welding tungsten types?

• A. Pure tungsten only
• B. Thoriated tungsten only
• C. Lanthanated tungsten only
• D. Pure or zirconated (green or brown)

Answer: (D)

When TIG welding aluminum, you’re using AC current, so the electrode needs to start and sustain an arc cleanly while resisting contamination from the oxide layer that aluminum forms. Pure tungsten works well for AC because it provides a stable, clean arc with minimal electrode contamination, and zirconated tungsten (tungsten with zirconium oxide) adds even easier arc starting and good stability for AC. Together, these two types cover the common, practical options welders rely on for aluminum. Thoriated tungsten is generally avoided for aluminum and AC because it introduces radioactive material and can behave less predictably on AC, and while lanthanated tungsten is versatile, the statement that both pure and zirconated tungsten are suitable for aluminum accurately reflects the typical practice.