Nano-phase W and W-Ti composite via gas-phase combustion synthesis

Nano-particulates of W and W-Ti have been synthesized by a gas-phase combustion process employing exchange reactions between sodium and metal chlorides. Gaseous reactants were introduced in a coflow diffusion-flame burner. To minimize agglomeration and protect the particles from contamination during subsequent exposure to atmosphere, the NaCl by product was condensed onto the particles within the flame. Resulting particles were unagglomerated, cubic or hexagonal in shape with an average size of ca. 30 nm. The nano-crystalline W and W-Ti particulates were consolidated by hot pressing at temperatures of 1000 to 1200°C in argon atmosphere. The consolidates were found to be greater than 96% dense with grain sizes of 30 to 40 nm.