Synthesis of high-strength W-Ta ultrarine-grain composites

TitleSynthesis of high-strength W-Ta ultrarine-grain composites
Publication TypeJournal Article
Year of Publication2008
AuthorsOtt RT, Yang XY, Guyer DE, Chauhan S, Sordelet DJ
Journal TitleJournal of Materials Research
Date PublishedJan
Type of ArticleArticle
ISBN Number0884-2914
Accession NumberISI:000252291200019
Keywordsbehavior, COMPRESSION, deformation, diffraction, LOCALIZATION, mechanical-properties, microstructure, NANOCRYSTALLINE, POWDER, TUNGSTEN

Bulk samples of an ultrafine-grained tungsten-tantalum composite alloy have been synthesized by consolidating mechanically milled composite powders. The grain growth during densification is limited due to the submicron-scale layering of the individual metals in the composite particles and the relatively low sintering temperature (1300 degrees C). The ultrafine microstructure of the high-density (similar to 99% theoretical density) samples leads to a high yield stress of similar to 3 GPa under quasi-static uniaxial compression. A tendency for Ta-rich solid-solution formation during densification was observed, and the high-temperature phase equilibria in the composite powders were examined further using high-energy x-ray diffraction at temperatures up to 1300 degrees C.

Alternate JournalJ. Mater. Res.