Phase analysis and lattice mismatches in superalloys DT706 and Inconel 706
Creators
- 1. Institute for Materials Science, Darmstadt University of Technology, Petersenstrasse 23, 64287 Darmstadt (Germany)
- 2. IFW, TU Braunschweig, Langer Kamp 8, 38106 Braunschweig (Germany)
- 3. ZWE FRM-II, Munich University of Technology, Lichtenbergstrasse 1, 85747 Garching (Germany)
- 4. Institute for Applied Physics, ETH Zurich, 8093 Zurich (Switzerland)
- 5. Hahn-Meitner-Institut, Glienicker Strasse 100, 14109 Berlin (Germany)
Description
Superalloys DT706 and Inconel 706 have been analysed by neutron diffraction and TEM to determine volume fractions of hardening phases and lattice mismatches. Inconel 706 is a γ'+γ'' precipitation hardened alloy, used in gas turbines. The limited thermal stability of γ' and γ'' phases restricts its applications to 600 deg. C. The new Fe-Ni-based superalloy DT706 was developed from Inconel 706 by altering the (Al+Ti)/Nb ratio to stabilise γ' over the metastable γ'' phase for applications beyond 700 deg. C. Both alloys have been heat treated according to a modified three-step cycle (MST). Higher volume fractions of γ' phase and lower amounts of γ'' phase have been observed in DT706 compared to Inconel 706. The γ'/γ lattice mismatches of both DT706 and Inconel 706 are positive (i.e. a(γ')>a(γ)), with DT706 having the minor misfit. TEM studies revealed morphological differences of γ'/γ'' precipitates between DT706 and Inconel 706. The results indicate that the desired improvement of the microstructural stability in DT706 is achievable
Additional details
Identifiers
- DOI
- 10.1016/j.physb.2006.06.108;
- PII
- S0921-4526(06)01380-9;
Publishing Information
- Journal Title
- Physica. B, Condensed Matter
- Journal Volume
- 385-386
- Journal Page Range
- p. 594-596
- ISSN
- 0921-4526
- CODEN
- PHYBE3
Conference
- Title
- 8. international conference on neutron scattering
- Dates
- 27 Nov - 2 Dec 2005
- Place
- Sydney (Australia)
INIS
- Country of Publication
- Netherlands
- Country of Input or Organization
- International Atomic Energy Agency (IAEA)
- INIS RN
- 38076482
- Subject category
- S75: CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY;
- Resource subtype / Literary indicator
- Conference
- Descriptors DEI
- CONCENTRATION RATIO; CRYSTAL DEFECTS; HARDENING; HEAT TREATMENTS; INCONEL 706; MICROSTRUCTURE; NEUTRON DIFFRACTION; PHASE STABILITY; PHASE STUDIES; PRECIPITATION; STRUCTURAL CHEMICAL ANALYSIS
- Descriptors DEC
- ALLOY-NI41FE40CR16NB3; ALLOYS; CHROMIUM ALLOYS; COHERENT SCATTERING; CORROSION RESISTANT ALLOYS; CRYSTAL STRUCTURE; DIFFRACTION; DIMENSIONLESS NUMBERS; HEAT RESISTANT MATERIALS; HEAT RESISTING ALLOYS; INCONEL ALLOYS; IRON ALLOYS; MATERIALS; NICKEL ALLOYS; NICKEL BASE ALLOYS; NIOBIUM ALLOYS; SCATTERING; SEPARATION PROCESSES; STABILITY; TITANIUM ALLOYS; TRANSITION ELEMENT ALLOYS
Optional Information
- Copyright
- Copyright (c) 2006 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.