Precipitation in Alloy 718 : A combined AEM and APFIM investigation

Conference · Tue Jan 01 04:00:00 EST 1991

OSTI ID:5676309

Burke, M G ^[1]; Miller, M K ^[2]

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1. Westinghouse Electric Corp., Pittsburgh, PA (USA). Science and Technology Center
2. Oak Ridge National Lab., TN (USA). Metals and Ceramics Div.

The desirable mechanical properties of nickel-base superalloy Alloy 718 are associated with a complex multiphase microstructure that is produced by a multistage heat treatment. In this investigation, the primary matrix strengthening phases ({gamma}{double prime} and {gamma}{prime}) and grain boundary phases ({delta} and Laves) formed during various aging treatments have been characterized by a combination of analytical electron microscopy and atom probe field ion microscopy. Detailed structural and chemical analyses have been performed to identify the phases and provide information concerning the precipitation sequence for the primary {gamma}{double prime} and {delta} phases. The results of this investigation have revealed that there is a wide variation in the composition of the phases and that their compositions are affected by the thermal treatment and location within the complex microstructure. 8 refs., 10 figs., 6 tabs.

• Research Organization: Westinghouse Electric Corp., Pittsburgh, PA (USA). Science and Technology Center
• Sponsoring Organization: DOE; USDOE, Washington, DC (USA)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5676309
• Report Number(s): CONF-910614-3; ON: DE91009918
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
AGING
ALLOY-NI53CR19FE19NB5MO3
ALLOYS
ALUMINIUM ADDITIONS
ALUMINIUM ALLOYS
CARBIDES
CARBON COMPOUNDS
CHEMICAL ANALYSIS
CHEMICAL COMPOSITION
CHROMIUM ALLOYS
CORROSION RESISTANT ALLOYS
CRYSTAL STRUCTURE
DATA
ELECTRON MICROSCOPY
EXPERIMENTAL DATA
GRAIN BOUNDARIES
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
HEAT TREATMENTS
INCONEL 718
INCONEL ALLOYS
INFORMATION
ION MICROPROBE ANALYSIS
IRON ALLOYS
LAVES PHASES
MATERIALS
MECHANICAL PROPERTIES
MICROANALYSIS
MICROSCOPY
MICROSTRUCTURE
MOLYBDENUM ALLOYS
NICKEL ALLOYS
NICKEL BASE ALLOYS
NIOBIUM A
NONDESTRUCTIVE ANALYSIS
NUMERICAL DATA
PRECIPITATION
SEPARATION PROCESSES