Non-Radioactive Tungsten Materials

Two significant alternative, non-radioactive tungsten materials have been developed. The first one, introduced in the 1980's, is most commonly available as 2% ceriated tungsten. This material is commonly used for lower amperage DC welding applications. In fact, it holds a very high market share in sales for the orbital welding process.

More recently, 1½% lanthanated tungsten has emerged as what could be the future standard for tungsten electrodes. The 1½% by weight content (as opposed to 2%) was chosen by three of the largest manufacturers as the optimum content amount based on scientific studies which showed that this content amount most closely mirrors the conductivity characteristics of 2% thoriated tungsten. Therefore, welders can usually easily replace their radioactive 2% thoriated material with this tungsten and not have to make any welding program changes. In addition, since the lanthanum oxide material is less dense that thorium oxide, a stick of 1½% (by weight) lanthanated tungsten actually contains 15% more oxides by volume than a stick of 2% (by weight) thoriated tungsten. This aids in arc starting and stability, as well as longevity, because the additional volume of oxides keep the tip cooler.

Finally, 1½% lanthanated tungsten is suitable for both AC and DC welding applications. Therefore, facilities that stock both 2% thoriated tungsten for DC welding and another tungsten type (usually pure or zirconiated tungsten) for AC welding, could stock only one tungsten type.