The effects of alloy purity on the mechanical behavior of soft oriented NiAl single crystals

Journal Article · Fri Oct 15 04:00:00 EDT 1993 · Scripta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-716X(93)90187-W· OSTI ID:6151483

Weaver, M L; Kaufman, M J ^[1]; Noebe, R D ^[2]

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1. Univ. of Florida, Gainesville, FL (United States). Dept. of Materials Science and Engineering
2. NASA Lewis Research Center, Cleveland, OH (United States)

Alloys based on the intermetallic compound NiAl are considered good candidates for high temperature structural applications due to their excellent oxidation resistance, low density and high thermal conductivity compared to nickel-base superalloys. In spite of these advantages, their developments into viable engineering materials has been limited by low ductility at ambient temperatures. However, recent efforts have resulted in room temperature tensile elongations of up to 6% for doped NiAl single crystals containing microalloying additions of Fe, Mo or Ga. The mechanism behind this increased ductility is unknown buy may be related to a gettering phenomenon since it is realized that some substitutional elements and interstitial impurities can cause significant embrittlement in bcc metals and B2 ordered compounds such as NiAl. Current observations are consistent with this viewpoint. Consequently, the purpose of this paper is to provide preliminary details concerning the effects of alloy purity on the mechanical properties of NiAl single crystals with differing impurity contents were studied. In addition, a NiAl alloy intentionally doped with Mo was investigated and a comparison of the mechanical properties of all three alloys is discussed in terms of relative compositions.

• DOE Contract Number: W-31109-ENG-38; FG02-89ER45403
• OSTI ID: 6151483
• Journal Information: Scripta Metallurgica et Materialia; (United States), Journal Name: Scripta Metallurgica et Materialia; (United States) Vol. 29:8; ISSN 0956-716X; ISSN SCRMEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
ALLOY SYSTEMS
ALLOYS
ALUMINIUM ALLOYS
BINARY ALLOY SYSTEMS
INTERMETALLIC COMPOUNDS
MECHANICAL PROPERTIES
MOLYBDENUM ADDITIONS
MOLYBDENUM ALLOYS
NICKEL ALLOYS