Zirconiated Tungstens are only used on AC applications , usually welding aluminium and its alloys.
Zirconiated tungsten electrodes contain a minimum of 99.10% tungsten and 0.80% zirconium.
A Zirconiated tungsten electrode produces an extremely stable arc and
resists tungsten spitting. It is ideal for AC welding as it retains a
balled tip and has a high resistance to contamination. Its current
carrying capability is equal to or greater than thoriated tungsten.
Under no circumstances is zirconiated recommended for DC welding.