Abstract: A friction stir tool has an axis of rotation and a welding tip that is made of powdered metal material.

Abstract: Metallurgical powder compositions are provided that include calcium aluminate additives, i.e., calcium aluminate or calcium aluminate containing powders, to enhance the machinability and durability of compacted and sintered parts made therefrom. The compositions generally contain a metal-based powder, such as for example, an iron-based or nickel-based powder, that constitutes the major portion of the composition. Calcium aluminate additives are combined with the metal based powder by, for example, admixing or bonding. Optionally, common alloying powders, lubricants, binding agents, and other powder metallurgy additives can be combined with the metallurgical powder composition. The metallurgical powder composition is used by compacting it in a die cavity to produce a “green” compact that may then be sintered, preferably at relatively high temperatures.