Precipitation in Alloy 718 : A combined AEM and APFIM investigation

Conference · Tue Jan 01 00:00:00 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: USDOE; USDOE, Washington, DC (USA)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5676309
• Report Number(s): CONF-910614-3; ON: DE91009918
• Resource Relation: Conference: Special emphasis symposium on superalloys 718, 625, and various derivatives, Pittsburgh, PA (USA), 23-26 Jun 1991
• Country of Publication: United States
• Language: English

Related Subjects

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