X-ray investigations on creep-deformed single crystals of the nickel-base superalloy CMSX-4

Journal Article · Mon May 01 04:00:00 EDT 1995 · Acta Metallurgica et Materialia

DOI:https://doi.org/10.1016/0956-7151(94)00407-9· OSTI ID:55329

Lang, C; Schneider, W; Mughrabi, H ^[1]

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1. Univ. Erlangen-Nuernberg, Erlangen (Germany). Inst. fuer Werkstoffwissenschaften

x-ray investigations were carried out on undeformed and creep-deformed single crystals of the {gamma}{prime}-hardened nickel-base superalloy CMSX-4 in order to obtain information about the microstructural changes induced by creep deformation. For this purpose x-ray rocking curves and x-ray topographs obtained by the method of Berg and Barrett were analyzed. In undeformed crystals, characteristic mutual misorientations of up to {approx} 30{prime} between neighboring dendrites were detected and characterized. The study of deformed crystals showed that the dislocations and dislocation networks formed during deformation produce additional lattice misorientations. In specimens creep-deformed at 800 C in which the cuboidal {gamma}{prime}-particle morphology has been preserved, a marked difference in the frequencies of lattice rotations around axes parallel and perpendicular to the tensile axis, respectively, could be deduced from rocking-curve broadening. This is caused by the different states of stress in the {gamma}-matrix channels which lie parallel and perpendicular to the stress axis, respectively. On the other hand, after creep deformation at 950 C, a directionally coarsened {gamma}/{gamma}{prime} structure prevails, giving rise to a distinctly different rocking-curve broadening, indicating that only the lattice misorientations around axes perpendicular to the stress axis are enhanced by creep deformation.

• OSTI ID: 55329
• Journal Information: Acta Metallurgica et Materialia, Journal Name: Acta Metallurgica et Materialia Journal Issue: 5 Vol. 43; ISSN 0956-7151; ISSN AMATEB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CREEP
DEFORMATION
DISLOCATIONS
HEAT TREATMENTS
METALLURGICAL EFFECTS
MICROSTRUCTURE
MONOCRYSTALS
NICKEL BASE ALLOYS