Fatigue crack growth behavior of Nb-10Si in-situ composites

Journal Article · Tue May 12 04:00:00 EDT 1998 · Scripta Materialia

DOI:https://doi.org/10.1016/S1359-6462(98)00106-7· OSTI ID:619522

Zinsser, Jr, W A; Lewandowski, J J ^[1]

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1. Case Western Reserve Univ., Cleveland, OH (United States)

One intermetallic silicide that has received recent attention is Nb{sub 5}Si{sub 3}. In addition to its high melting temperature (T{sub mp} = 2,753 K), Nb{sub 5}Si{sub 3} also exhibits a lower density than nickel-base superalloys. Although Nb{sub 5}Si{sub 3} is expected to exhibit high temperature strength and creep resistance, the low fracture toughness (1 to 3 MPa{radical}m), ductility, and estimated fatigue threshold behavior ({Delta}K{sub th} < 3 MPa{radical}m) at ambient temperatures would severely limit the usefulness of such a material. In order to improve upon the low temperature fracture toughness of the Nb{sub 5}Si{sub 3} intermetallic the introduction of ductile reinforcements was proposed. While previous work on these composites was focused on the fracture toughness and R-curve behavior of the Nb-10 at.% Si composite, as well as the toughness and cleavage fracture stress of the Nb-Si{sub (ss)} constituent, little information exists on their fatigue crack growth and threshold behavior. The purpose of this work was to characterize the fatigue crack growth behavior of the Nb-10 at.% Si composite.

• OSTI ID: 619522
• Journal Information: Scripta Materialia, Journal Name: Scripta Materialia Journal Issue: 12 Vol. 38; ISSN 1359-6462; ISSN SCMAF7
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COMPOSITE MATERIALS
CRACK PROPAGATION
FATIGUE
HEAT RESISTANT MATERIALS
NIOBIUM BASE ALLOYS
NIOBIUM SILICIDES
SILICON ALLOYS