Christian Gadelmeier
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Christian Gadelmeier has a total of 10 co-authors. Here are the top co-authors by number of shared publications:
- Uwe Glatzel
University of Bayreuth
2 shared publications - Anna Maria Manzoni
Department of Materials Engineering, Federal Institute of Materials Research and Testing (BAM), Unter der Eichen 87, 12205 Berlin, Germany
1 shared publication - Fabian Krieg
Metals and Alloys Department, University of Bayreuth, 95447 Bayreuth, Germany
1 shared publication - Felix Schleifer
Metals and Alloys, University of Bayreuth, Bayreuth, Germany
1 shared publication - Michael Feuerbacher
Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons ER-C-1, Forschungszentrum Jülich GmbH, Jülich, 52425, Germany
1 shared publication - Mike Mosbacher
Metals and Alloys Department, University of Bayreuth, 95447 Bayreuth, Germany
1 shared publication
Latest Publications
- Open Access
Quantification of Solid Solution Strengthening and Internal Stresses through Creep Testing of Ni-Containing Single Crystals at 980 °C
Various alloy compositions were cast as single crystals in a Bridgman vacuum induction furnace and creep tested at 980 °C: pure Ni, the equiatomic alloys CoCrNi and CrMnFeCoNi (Cantor alloy), single-phase fcc (Ni) solid solution alloys (with the composition of the matrix-phase of CMSX-3 and CMSX-4), and two-phase Ni-based superalloys CMSX-3 and CMSX-4. Due to the single-crystal state, grain size effects, grain boundary sliding, and grain boundary diffusion can be excluded. The results identify two major strengthening mechanisms: solid solution strengthening and other mechanisms summarized as precipitation hardening. Configurational entropy does not increase creep strength: The Cantor alloy, with the highest configurational entropy of all alloys tested, shows a weak and similar creep strength at 980 °C in comparison to pure Ni with zero configurational entropy. The element Re is a very effective strengthener, both in single-phase fcc (Ni) solid solution alloys as well as in two-phase superalloys. Quantitative estimations of different strengthening mechanisms: internal back stress, misfit stresses, Orowan bowing, and γ′-phase cutting (in the case of two-phase superalloys) are presented. Finite element simulations allow estimating the influence of solid solution strengthening of the matrix on the creep behavior of the two-phase superalloys.
Open AccessQuantification of Solid Solution Strengthening and Internal Stresses through Creep Testing of Ni-Containing Single Crystals at 980 °C
Various alloy compositions were cast as single crystals in a Bridgman vacuum induction furnace and creep tested at 980 °C: pure Ni, the equiatomic alloys CoCrNi and CrMnFeCoNi (Cantor alloy), single-phase fcc (Ni) solid solution alloys (with the composition of the matrix-phase of CMSX-3 and CMSX-4), and two-phase Ni-based superalloys CMSX-3 and CMSX-4. Due to the single-crystal state, grain size effects, grain boundary sliding, and grain boundary diffusion can be excluded. The results identify two major strengthening mechanisms: solid solution strengthening and other mechanisms summarized as precipitation hardening. Configurational entropy does not increase creep strength: The Cantor alloy, with the highest configurational entropy of all alloys tested, shows a weak and similar creep strength at 980 °C in comparison to pure Ni with zero configurational entropy. The element Re is a very effective strengthener, both in single-phase fcc (Ni) solid solution alloys as well as in two-phase superalloys. Quantitative estimations of different strengthening mechanisms: internal back stress, misfit stresses, Orowan bowing, and γ′-phase cutting (in the case of two-phase superalloys) are presented. Finite element simulations allow estimating the influence of solid solution strengthening of the matrix on the creep behavior of the two-phase superalloys.
- Open Access
Temperature Dependent Solid Solution Strengthening in the High Entropy Alloy CrMnFeCoNi in Single Crystalline State
The main difference between high entropy alloys and conventional alloys is the solid solution strengthening effect, which shifts from a single element to a multi-element matrix. Little is known about the effectiveness of this effect at high temperatures. Face-centered cubic, equiatomic, and single crystalline high entropy alloy CrMnFeCoNi was pre-alloyed by arc-melting and cast as a single crystal using the Bridgman process. Mechanical characterization by creep testing were performed at temperatures of 700, 980, 1100, and 1200 °C at different loads under vacuum and compared to single-crystalline pure nickel. The results allow a direct assessment of the influence of the chemical composition without any disturbance by grain boundary sliding or diffusion. The results indicate different behaviors of single crystalline pure nickel and CrMnFeCoNi. At 700 °C CrMnFeCoNi is more creep-resistant than Ni, but at 980 °C both alloys show a nearly similar creep strength. Above 980 °C the creep behavior is identical and the solid solution strengthening effect of the CrMnFeCoNi alloy disappears.
Open AccessTemperature Dependent Solid Solution Strengthening in the High Entropy Alloy CrMnFeCoNi in Single Crystalline State
The main difference between high entropy alloys and conventional alloys is the solid solution strengthening effect, which shifts from a single element to a multi-element matrix. Little is known about the effectiveness of this effect at high temperatures. Face-centered cubic, equiatomic, and single crystalline high entropy alloy CrMnFeCoNi was pre-alloyed by arc-melting and cast as a single crystal using the Bridgman process. Mechanical characterization by creep testing were performed at temperatures of 700, 980, 1100, and 1200 °C at different loads under vacuum and compared to single-crystalline pure nickel. The results allow a direct assessment of the influence of the chemical composition without any disturbance by grain boundary sliding or diffusion. The results indicate different behaviors of single crystalline pure nickel and CrMnFeCoNi. At 700 °C CrMnFeCoNi is more creep-resistant than Ni, but at 980 °C both alloys show a nearly similar creep strength. Above 980 °C the creep behavior is identical and the solid solution strengthening effect of the CrMnFeCoNi alloy disappears.