Effect of Grain-Boundary Characteristics on Castability of Nickel-Base Superalloys

Beitrag in einer Fachzeitschrift
(Originalarbeit)


Details zur Publikation

Autor(en): Zhang J, Singer R
Zeitschrift: Metallurgical and Materials Transactions A-Physical Metallurgy and Materials Science
Jahr der Veröffentlichung: 2004
Heftnummer: 3
Seitenbereich: 939-946
ISSN: 1073-5623
Sprache: Englisch


Abstract


Hot tearing susceptibility of two Ni-base superalloys, IN792 and CM247, during directional solidification was studied. Effects of grain-boundary (GB) misorientation on castability were examined by casting single-crystal (SC) and bicrystal (BC) specimens. Crack-free specimens were obtained in castings with GB misorientation angles of less than ∼12 deg. Severe cracking occurred if the GB angle was greater than 25 deg. Secondary dendrite arm length right at the GB was found to be larger than in the GB vicinity and to increase with GB misorientation. The amount of eutectic melt and foreign element segregation is also larger at the GB. The greater susceptibility of the GB to hot tearing is almost certainly caused by reduced strength compared to the grain interior. The reduced strength is either due to reduced secondary arm bridging because of geometrical constraints or due to the existence of a thin liquid film as a result of stronger segregation.



FAU-Autoren / FAU-Herausgeber

Singer, Robert Prof. Dr.-Ing.
Lehrstuhl für Werkstoffwissenschaften (Werkstoffkunde und Technologie der Metalle)


Zitierweisen

APA:
Zhang, J., & Singer, R. (2004). Effect of Grain-Boundary Characteristics on Castability of Nickel-Base Superalloys. Metallurgical and Materials Transactions A-Physical Metallurgy and Materials Science, 3, 939-946.

MLA:
Zhang, Jian, and Robert Singer. "Effect of Grain-Boundary Characteristics on Castability of Nickel-Base Superalloys." Metallurgical and Materials Transactions A-Physical Metallurgy and Materials Science 3 (2004): 939-946.

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Zuletzt aktualisiert 2018-08-08 um 00:23