Alternatives to thorium additions to tungsten-based materials

Thorium and thoria additions are used in tungsten-based materials for a variety of performance-enhancing reasons, including better electron emissivity of electrodes (resulting in improved arcing behavior), higher strength and hardness,finer grain size, and better machinability. The resulting material’s radioactive potential, however, makes it subject to stringent legislation, which makes handling, use, recycling, and disposal more difficult. Therefore, research is being done on alternative additives that exhibit the same advantages as thoriated tungsten but without the drawbacks. In this respect, lanthanum and cerium-oxide doping represent competitive alternatives.