In Situ Micro-Pillar Compression to Examine Radiation-Induced Hardening Mechanisms of FeCrAl Alloys

2021-01-01
Cui, Yuchi
Aydoğan Güngör, Eda
Gigax, Jonathan G.
Wang, Yongqiang
Misra, Amit
Maloy, Stuart A.
Li, Nan
© 2020The effects of 5 MeV Fe2+ ion irradiation at 300°C on the microstructure evolution and deformation behavior of a FeCrAl C26M alloy are presented. It has been found that dislocation loop density increases an order of magnitude from 1 dpa to 16 dpa irradiations, whereas, the dislocation loop size saturates with increasing damage. Micropillars, 600 nm in diameter and 1.3 µm in height, were fabricated and compressed inside grains with , and crystallographic orientations, respectively. {112} has been identified as the primary slip system in both unirradiated and irradiated alloys. The increase in yield stress after irradiation is observed with measurable variation along and vs. along . By applying the Orowan dispersed barrier model, the increase of yield stress is found mainly due to the slip resistance of radiation generated defect loops. Detailed transmission electron microscopy (TEM) studies were performed to quantify the Burgers vector and the distribution of irradiation induced dislocations at elevated strains. It is revealed that localized shear instability is caused by avalanche slip events of ½ dislocations gliding out of tested pillars. Simultaneously, a large number of sessile/immobile dislocations formed in the vicinity of slip band, leading to the hardening at elevated strains.
Acta Materialia

Suggestions

Temperature dependent dispersoid stability in ion-irradiated ferritic-martensitic dual-phase oxide-dispersion-strengthened alloy: Coherent interfaces vs. incoherent interfaces
Chen, Tianyi; Gigax, Jonathan G.; Price, Lloyd; Chen, Di; Ukai, S.; Aydoğan Güngör, Eda; Maloy, S. A.; Garner, F. A.; Shao, Lin (Elsevier BV, 2016-09-01)
In this study, the microstructure of a 12Cr ferritic-martensitic oxide-dispersion-strengthened (ODS) alloy is studied before and after Fe ion irradiation up to 200 peak displacements per atom (dpa). Irradiation temperature ranges from 325 to 625 degrees C. Before irradiation, both coherent and incoherent dispersoids exist in the matrix. In response to irradiation, the mean sizes of dispersoids in both the ferrite and tempered martensite phases change to equilibrium values that increase with irradiation temp...
Detailed transmission electron microscopy study on the mechanism of dislocation loop rafting in tungsten
El-Atwani, O.; Aydogan, E.; Esquivel, E.; Efe, Mert; Wang, Y. Q.; Maloy, S. A. (Elsevier BV, 2018-04-01)
Dislocation loop rafting and dislocation decoration have been previously observed in neutron and heavy ion irradiated materials. Understanding the fundamental aspects of these phenomena assist in evaluating irradiation damage of nuclear materials. Multiple different mechanisms have been suggested to explain loop rafting. Here, we performed a detailed transmission electron microscopy study on dislocation loop rafts in heavy ion irradiated tungsten. Different imaging conditions showed that the rafts are of B...
Evolution of magnetic and structural properties of TiO2 with Co-doping
Topal, Ugur; Ozkan, Husnu; Bakan, Halil I.; Cankur, Oktay; Topal, Kevser (Elsevier BV, 2008-03-15)
This paper presents the phase formations and magnetic properties of Co-doped TiO2 synthesized by the colloidal and ammonium nitrate melt techniques (ANMT). The phase formations and ferromagnetic properties were studied with XRD and SQUID magnetometry. Crystallization of the TiO2 rutile lattice was completed at 1000 degrees C and that was preserved during annealing up to 1300 degrees C. For the samples annealed at 1200 degrees C, elemental analysis has shown that the colloidal technique leads to a single-pha...
Nano-scale phase separation in amorphous Fe-B alloys: Atomic and cluster ordering
AYKOL, Muratahan; Mehrabov, Amdulla; Akdeniz, Mahmut Vedat (Elsevier BV, 2009-01-01)
Nano-scale phase separation encountered in metallic glasses is investigated for amorphous Fe80B20 and Fe83B17 alloys in an interaction field calculated via electronic theory of alloys in pseudopotential approximation combined with MC equilibration and reverse MC simulation. The phenomenon is identified regarding three topological aspects: (1) pure Fe-clusters as large as similar to 0.9 nm and pure Fe-contours similar to 0.72 nm thick are found to exist; (2) Fe-rich highly deformed-bcc regions are observed; ...
Initial crystallization in a nanostructured Al-Sm rare earth alloy
Kalay, Yunus Eren; Chumbley, L. S.; Kramer, M. J.; Anderson, I. E. (Elsevier BV, 2010-06-15)
The transformation kinetics and microstructural evolution during initial crystallization in highly driven Al(90)Sm(10) were investigated using transmission electron microscopy (TEM). conventional Cu K(alpha) and high-energy synchrotron X-ray diffraction (HEXRD) and differential scanning calorimetry (DSC). The highest cooling rate obtained in this study yielded a high number density of fcc-Al nanocrystals, with sizes on the order of 2-5 nm, embedded in a disordered matrix rich in an Al-Sm medium range order ...
Citation Formats
Y. Cui et al., “In Situ Micro-Pillar Compression to Examine Radiation-Induced Hardening Mechanisms of FeCrAl Alloys,” Acta Materialia, pp. 255–265, 2021, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/69924.