Deformation microstructures after low-cycle fatigue at 950 C in Ni-based superalloys: The effect of test conditions

Journal Article · Sat Oct 01 00:00:00 EDT 1994 · Scripta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-716X(94)90480-4· OSTI ID:7244379

Decamps, B ^[1]; Brien, V ^[2]; Morton, A J ^[3]

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1. Univ. Paris-Sud, Orsay (France). Lab. de Metallurgie Structurale
2. CNRS-ONERA, Chatillon (France). Lab. d'Etude des Microstructures
3. CSIRO, Clayton, Victoria (Australia). Div. of Material Science and Technology

The correlation between microstructure and stress softening during low cycle fatigue tests at high temperature ([ge] 950 C) has been the subject of extensive studies for various nickel based superalloys. The situation appears very complex since many parameters, some of which are interdependent, affect the development of the microstructure. The general tendency is to relate cycling softening to coarsening of the [gamma] precipitates and the resulting dissolution of the interfacial dislocation networks. While the presence of superlattice stacking faults is well established for some alloys deformed at intermediate temperature, the situation at high temperature is not so clear. In this paper, microstructures resulting from low cycle fatigue tests at imposed stress and imposed strain are compared to those resulting from earlier monotonic tensile and compressive tests where the formation of superlattice stacking faults, responsible for the deformation, has been explained and related to the asymmetry of deformation under tensile and compressive load.

• OSTI ID: 7244379
• Journal Information: Scripta Metallurgica et Materialia; (United States), Vol. 31:7; ISSN 0956-716X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
NICKEL BASE ALLOYS
DEFORMATION
MICROSTRUCTURE
FATIGUE
MECHANICAL TESTS
STATIC LOADS
TEMPERATURE RANGE 1000-4000 K
ALLOYS
MATERIALS TESTING
MECHANICAL PROPERTIES
NICKEL ALLOYS
TEMPERATURE RANGE
TESTING
360102* - Metals & Alloys- Structure & Phase Studies
360103 - Metals & Alloys- Mechanical Properties