Friction stir tool
AssigneesHitachi, Ltd., Tohoku University
InventorsSeunghwan Park, Satoshi Hirano, Shinya Imano, Jun Sato, Hiroyuki Kokawa, Yutaka Sato, Kiyohito Ishida, Toshihiro Omori
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Abstract
It is an object to provide a friction stir tool excellent in productivity, high temperature strength, and wear resistance at high temperatures. The friction stir tool is formed of a Co-based alloy comprising crystal grains containing a γ′ precipitate phase dispersed and precipitated therein, and a crystal grain boundary region and a precipitate phase between adjacent crystal grains, in which the precipitate phase is at least one phase selected from a μ phase, a Laves phase and a carbide phase.
Claims10
A friction stir tool formed of a Co-based alloy having a γ phase with an A1 structure and a γ′ phase with an L12 structure precipitated in the γ phase, the γ′ phase comprising Co3(Al,W), and the γ′ phase being contained in the γ phase in an amount of 10% to 80% in terms of volume fraction, being formed by precision casting, the Co-based alloy including 30-50 at. % of Ni, and the γ′ phase thereof having a solid solution forming temperature higher than 1,000° C., wherein the Co-based alloy contains a precipitate selected from a μ phase, a Laves phase and a carbide.
Dependencies are inferred from the claim text.