% IMPORTANT: The following is UTF-8 encoded. This means that in the presence % of non-ASCII characters, it will not work with BibTeX 0.99 or older. % Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or % “biber”. @ARTICLE{Kmmel:480795, author = {Kümmel, Frank and Fritton, Massimo and Solís, Cecilia and Kriele, Armin and Stark, Andreas and Gilles, Ralph}, title = {{N}ear-{S}urface and {B}ulk {D}issolution {B}ehavior of $γ′$ {P}recipitates in {N}ickel-{B}ased {VDM}$^®$ {A}lloy 780 {S}tudied with {I}n-{S}itu {L}ab-{S}ource and {S}ynchrotron {X}-ray {D}iffraction}, journal = {Metals}, volume = {12}, number = {7}, issn = {2075-4701}, address = {Basel}, publisher = {MDPI}, reportid = {PUBDB-2022-03968}, pages = {1067}, year = {2022}, abstract = {The dissolution of nano-sized Ni3Al-based $γ′$ precipitates was investigated in the newly developed polycrystalline nickel-based VDM$^®$ Alloy 780 at the surface and in the bulk region with in-situ lab-source and synchrotron X-ray diffraction. These studies are important in obtaining a deeper understanding of the strengthening mechanism responsible for the stability and long service lives of such superalloys. We found that the dissolution behavior of the $γ′$ phase is very similar at the surface and in the bulk region, but small deviations were detected. The dissolution of $γ′$ starts at around 800 °C and no $γ′$ was found at temperatures exceeding 970 °C. As a result, the elements Al and Nb, which were bound in the $γ′$ phase, dissolved into the $γ$ matrix and strongly increased the $γ$ lattice parameter, as their atomic size is larger than the $γ$-forming elements Ni, Co, and Cr. However, this effect was suppressed in the surface area. A second matrix $γ$ phase was detected at the same temperature range as that of the dissolution of the $γ′$ phase in the lab-source XRD measurements. The newly formed $γ$-2 phase had a smaller lattice parameter than that of the initial $γ$ matrix. We propose that the $γ$-2 matrix phase is a result of high-temperature surface oxidation, which consumes, among other elements, Al and Nb and, therefore, leads to the smaller $γ$ lattice parameter.}, cin = {DOOR ; HAS-User / TUM / Hereon}, ddc = {530}, cid = {I:(DE-H253)HAS-User-20120731 / I:(DE-588b)36241-4 / I:(DE-H253)Hereon-20210428}, pnm = {6G3 - PETRA III (DESY) (POF4-6G3)}, pid = {G:(DE-HGF)POF4-6G3}, experiment = {EXP:(DE-H253)P-P07-20150101}, typ = {PUB:(DE-HGF)16}, UT = {WOS:000834415900001}, doi = {10.3390/met12071067}, url = {https://bib-pubdb1.desy.de/record/480795}, }