Advanced Scale Bridging Microstructure Analysis of Single Crystal Ni-Base Superalloys

0449621 - ÚFM 2016 RIV DE eng J - Článek v odborném periodiku
Parsa, A. B. - Wollgramm, P. - Buck, H. - Somsen, C. - Kostka, A. - Povstugar, I. - Choi, P.-P. - Raabe, D. - Dlouhý, Antonín - Müller, J. - Spiecker, E. - Demtroder, K. - Schreuer, J. - Neuking, K. - Eggeler, G.
Advanced Scale Bridging Microstructure Analysis of Single Crystal Ni-Base Superalloys.
Advanced Engineering Materials. Roč. 17, č. 2 (2015), s. 216-230. ISSN 1438-1656. E-ISSN 1527-2648
Institucionální podpora: RVO:68081723
Klíčová slova: High temperature materials * Nickel based superalloys * EPMA * HRTEM
Kód oboru RIV: JG - Hutnictví, kovové materiály
Impakt faktor: 1.817, rok: 2015

In the present work, we show how conventional and advanced mechanical, chemical, and microstructural methods can be used to characterize cast single crystal Ni-base superalloy (SX) plates across multiple length scales. Two types of microstructural heterogeneities are important, associated with the castmicrostructure (dendrites (D) and interdendritic (ID) regions - large scale heterogeneity) and with the well-known γ/γ′ microstructure (small scale heterogeneity). We can combine large scale (EPMA) and small-scale analytical methods (APT) to obtain reasonable estimates for γ′ volume fractions in the dendrites and in the ID regions. The chemical and mechanical properties of the SX plates studied in the present work are homogeneous, when they are determined from volumes with dimensions, which are significantly larger than the dendrite spacing. We highlight the potential of HRTEM and APT to contribute to a better understanding of the role of dislocations during coarsening of the γ′ phase and the effect of cooling rates after high temperature exposure on the microstructure.
Trvalý link: http://hdl.handle.net/11104/0251148