Solidification sequence and carbide precipitation in Ni-base superalloys IN718, IN625 AND IN939
2005 (English)In: High Temperature Materials and Processes, ISSN 0334-6455, Vol. 24, no 4, 239-258 p.Article in journal (Refereed) Published
Differential Thermal Analysis (DTA) and Directional Solidification and Quenching (DSQ) were used to evaluate the solidification and precipitation sequence for the Ni-base superalloys IN718, IN625 and IN939. They all showed a similar precipitation sequence, with an initial precipitation of gamma dendrites, followed by an intermediate non-invariant divorced eutectic reaction of type L -> gamma + MC, and a final eutectic precipitation of Laves phase for alloy IN718 and IN625 and of eta-phase for alloy IN939. The reaction temperatures and the amounts of carbides and of final precipitates were evaluated. Precipitated nitrides were found to act as nucleation sites for the precipitation of blocky carbides/carbonitrides, at low interdendritic supersaturation, while in interdendritic regions with high supersaturation, a 'script-like' carbide formation was found instead.
Place, publisher, year, edition, pages
2005. Vol. 24, no 4, 239-258 p.
IdentifiersURN: urn:nbn:se:kth:diva-15158ISI: 000233001700004ScopusID: 2-s2.0-27744449251OAI: oai:DiVA.org:kth-15158DiVA: diva2:333199
QC 201005252010-08-052010-08-05Bibliographically approved