Microstructure development and mechanical properties of cast and thermo-mechanically treated eutectic high-entropy alloys
The first part of this thesis work focuses on the as-cast microstructures of the eutectic and near-eutectic compositions of the AlCoCrFeNi2.1 system. Quantification of the phase volume and lamellar spacing is performed as a function of the Ni content. Orientation relationship and misorientation angle-axis changes in the five investigated alloys are also studied, with the previously unknown dependency of misorientation angle on the Ni content revealed. Some attention is also given to irregular microstructures in eutectic and near-eutectic compositions, which have not been discussed in previous studies.
In the second part of this thesis work, a systematic study of the recrystallization process and the correlation between microstructure and mechanical properties in the thermo-mechanically treated AlCoCrFeNi2.1 alloy is undertaken. Distinctive behavior of the constituent phases during recrystallization, with varying rates of recrystallization and grain growth are observed, providing new insights to the recrystallization process in this alloy. Furthermore, it is shown that by controlling the annealing temperature and time, hetero-deformation induced hardening could lead to abnormal hardening in the as-rolled alloy, providing a new strategy to achieve high-strength with acceptable ductility in EHEAs.
Chalmers, Industri- och materialvetenskap, Material och tillverkning
Quantification of microstructure in a eutectic high entropy alloy AlCoCrFeNi2.1
IOP Conference Series: Materials Science and Engineering,; Vol. 580(2019)
Paper i proceeding
Microstructural characterization of eutectic and near-eutectic AlCoCrFeNi high-entropy alloys
Journal of Alloys and Compounds,; Vol. 822(2020)
Artikel i vetenskaplig tidskrift
A. Lozinko, R. Gholizadeh, Y. Zhang, U. Klement, N. Tsuji, O. V. Mishin, S. Guo, Evolution of microstructure and mechanical properties during annealing of a heavily rolled AlCoCrFeNi2.1 eutectic high-entropy alloy
A. Lozinko, R. Gholizadeh, L. Han, U. Klement, N. Tsuji, S. Guo, Effect of annealing temperature on microstructure and mechanical properties of a partially recrystallized AlCoCrFeNi2.1 eutectic high-entropy alloy,
A. Lozinko, R. Gholizadeh, L. Han, U. Klement, N. Tsuji, S. Guo, Rapid annealing induced hardening in a cold-rolled AlCoCrFeNi2.1 eutectic high-entropy alloy
Eutektiska högentropilegeringar : en lovande ny klass av högtemperaturlegeringar
Vetenskapsrådet (VR) (2015-04087), 2016-01-01 -- 2020-12-31.
Metallurgi och metalliska material
Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 5068
Chalmers tekniska högskola
Virtual Development Laboratory (VDL), Chalmers Tvärgata 4C
Opponent: Professor Pasi Peura, Tampere University, Tampere, Finland