Abstract
The microstructure and tensile properties of the intermetallic γ-TiAl + α2-Ti3Al alloy Ti-45Al-6(Nb, Mo)-0.2B are studied after various heat and thermomechanical treatments. Its cast state is found to be characterized by a homogeneous, relatively fine-grained structure in the cases of both a model 30-g ingot and a bulk laboratory Φ120 × 180-mm ingot. The cast material subjected to heat treatment with furnace cooling and aging at T = 1100°C exhibits strength properties at T = 20-900°C that are relatively high for cast γ + α2 alloys. Due to the rational choice of the alloy, its thermomechanical treatment is facilitated, a fine-grained structure can easily be formed upon hot deformation, and a superplastic state with elongations in the test-temperature range T = 900-1000°C that are very large for γ + α2 alloys is reached. However, the high contents of niobium and molybdenum in the Ti-45Al-6(Nb, Mo)-0.2B alloy hinder the formation of an equilibrium lamellar structure upon heat treatment, and an increase in the aging temperature to T = 1100°C leads to the development of the α2 → ß(B2) phase transformation, which makes it impossible to reach a high level of the mechanical properties in the temperature range of the potential application of γ + α2 alloys. Our study has revealed that the compositions of the γ + α2 alloys need further optimization of the way of refining the niobium and molybdenum contents.
| Language | English |
|---|---|
| Pages | 641-648 |
| Number of pages | 8 |
| Journal | Physics of Metals and Metallography |
| Volume | 106 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - Dec 2008 |
| Externally published | Yes |
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Keywords
- microstructures
- thermomechanical treatments
- alloys
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Microstructure and mechanical properties of the intermetallic alloy Ti-45Al-6(Nb, Mo)-0.2B. / Imaev, V. M.; Imaev, R. M.; Oleneva, T. I.; Khismatullin, T. G.
In: Physics of Metals and Metallography, Vol. 106, No. 6, 12.2008, p. 641-648.Research output: Contribution to journal › Article
TY - JOUR
T1 - Microstructure and mechanical properties of the intermetallic alloy Ti-45Al-6(Nb, Mo)-0.2B
AU - Imaev, V. M.
AU - Imaev, R. M.
AU - Oleneva, T. I.
AU - Khismatullin, T. G.
PY - 2008/12
Y1 - 2008/12
N2 - The microstructure and tensile properties of the intermetallic γ-TiAl + α2-Ti3Al alloy Ti-45Al-6(Nb, Mo)-0.2B are studied after various heat and thermomechanical treatments. Its cast state is found to be characterized by a homogeneous, relatively fine-grained structure in the cases of both a model 30-g ingot and a bulk laboratory Φ120 × 180-mm ingot. The cast material subjected to heat treatment with furnace cooling and aging at T = 1100°C exhibits strength properties at T = 20-900°C that are relatively high for cast γ + α2 alloys. Due to the rational choice of the alloy, its thermomechanical treatment is facilitated, a fine-grained structure can easily be formed upon hot deformation, and a superplastic state with elongations in the test-temperature range T = 900-1000°C that are very large for γ + α2 alloys is reached. However, the high contents of niobium and molybdenum in the Ti-45Al-6(Nb, Mo)-0.2B alloy hinder the formation of an equilibrium lamellar structure upon heat treatment, and an increase in the aging temperature to T = 1100°C leads to the development of the α2 → ß(B2) phase transformation, which makes it impossible to reach a high level of the mechanical properties in the temperature range of the potential application of γ + α2 alloys. Our study has revealed that the compositions of the γ + α2 alloys need further optimization of the way of refining the niobium and molybdenum contents.
AB - The microstructure and tensile properties of the intermetallic γ-TiAl + α2-Ti3Al alloy Ti-45Al-6(Nb, Mo)-0.2B are studied after various heat and thermomechanical treatments. Its cast state is found to be characterized by a homogeneous, relatively fine-grained structure in the cases of both a model 30-g ingot and a bulk laboratory Φ120 × 180-mm ingot. The cast material subjected to heat treatment with furnace cooling and aging at T = 1100°C exhibits strength properties at T = 20-900°C that are relatively high for cast γ + α2 alloys. Due to the rational choice of the alloy, its thermomechanical treatment is facilitated, a fine-grained structure can easily be formed upon hot deformation, and a superplastic state with elongations in the test-temperature range T = 900-1000°C that are very large for γ + α2 alloys is reached. However, the high contents of niobium and molybdenum in the Ti-45Al-6(Nb, Mo)-0.2B alloy hinder the formation of an equilibrium lamellar structure upon heat treatment, and an increase in the aging temperature to T = 1100°C leads to the development of the α2 → ß(B2) phase transformation, which makes it impossible to reach a high level of the mechanical properties in the temperature range of the potential application of γ + α2 alloys. Our study has revealed that the compositions of the γ + α2 alloys need further optimization of the way of refining the niobium and molybdenum contents.
KW - microstructures
KW - thermomechanical treatments
KW - alloys
UR - http://www.scopus.com/inward/record.url?scp=57849152147&partnerID=8YFLogxK
U2 - 10.1134/S0031918X08120132
DO - 10.1134/S0031918X08120132
M3 - Article
VL - 106
SP - 641
EP - 648
JO - Physics of Metals and Metallography
T2 - Physics of Metals and Metallography
JF - Physics of Metals and Metallography
SN - 0031-918X
IS - 6
ER -