Rev.Adv.Mater.Sci. (RAMS)
No 8, Vol. 18, 2008, pages 711-715

CREEP TESTS OF ELECTRODEPOSITED NANOCRYSTALLINE Ni-W
ALLOYS AT ELEVATED TEMPERATURES

Tohru Yamasaki, Hitoshi Yokoyama and Takeshi Fukami

Abstract

High-strength nanocrystalline Ni-W alloys containing about 16.9 at.% W with average grain sizes of about 6 nm in diameter have been obtained by electrodeposition. At room temperature, the nominal tensile strength of the Ni-W alloy was attained to about 1600 MPa, while the plastic strain before fracture was a very low value of about 0.05%. In this case, highly localized shear bands were observed near the fractured surface of the tensile test specimen. When the samples were creep-tested at 300 œC for 120 h under the applied tensile stress of 326.7 MPa, plastic strain of about 0.7% without the formation of localized shear bands was observed.

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