Method for preparing ultra-fine grain titanium and titanium-alloy articles and articles prepared thereby

摘要

A method for preparing ultra-fine grain titanium or titanium-alloy articles (78) used for adjoining or assembling of detail components is disclosed. Coarse-grained titanium or titanium-alloy materials (52) typically are heated and forced under constant pressure through a friction stir processing tooling device (50) containing a stirring chamber (54) and a stirring rod (58). As the material is passed through the stirring chamber (54), the stirring rod (58) solutionizes the titanium or titanium-alloy material (52) and stirs the material to obtain a homogeneous or uniform material condition. As the processed material exits the stirring chamber (54) of the friction stir process tooling device (50), it reconsolidates as an extremely homogeneous structure possessing ultra-fine grain structure. Titanium or titanium-alloy materials (52) having been processed to achieve such ultra-fine grain material structure may then be manufactured into aerospace structural articles or components such as fasteners (78) that do not require a subsequent heat-treatment steps (Fig. 2). <IMAGE>