Effects of Tantalum on Microstructure Evolution and Mechanical Properties of High-Nb TiAl Alloys Reinforced by Ti2AlC
Experiments have been carried out to study the relationship between the addition of tantalum and microstructure, especially the formation of the B2 phase in lamellar colonies. The mechanical properties, with different contents of Ta, were also measured. Ti46Al8Nb2.6CxTa alloys were prepared by casti...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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American Association for the Advancement of Science (AAAS)
2019-01-01
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| Series: | Research |
| Online Access: | http://dx.doi.org/10.34133/2019/5143179 |
| _version_ | 1797286151722106880 |
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| author | Hongze Fang Ruirun Chen Yong Yang Yanqing Su Hongsheng Ding Jingjie Guo |
| author_facet | Hongze Fang Ruirun Chen Yong Yang Yanqing Su Hongsheng Ding Jingjie Guo |
| author_sort | Hongze Fang |
| collection | DOAJ |
| description | Experiments have been carried out to study the relationship between the addition of tantalum and microstructure, especially the formation of the B2 phase in lamellar colonies. The mechanical properties, with different contents of Ta, were also measured. Ti46Al8Nb2.6CxTa alloys were prepared by casting with the content of Ta varying from zero to 1.0 at.%. Experimental results show that the B2 phase forms in lamellar colonies with the addition of Ta, and its content increases when the content of Ta increases. Meanwhile, the γ phase decreases and the lattice parameter of the α2 phase increases. The size of the lamellar colony decreased from 29.9 to 21.6 μm. Ta dissolves into Ti2AlC by substitution, and its solubility is more than 1.1% tested by EDS. Nb, which is necessary for the formation of the B2 phase, comes from two aspects. The first is that Ta dissolves into the Ti2AlC and partly replaces the Nb atom and the second is the decrease in the γ phase because it has higher solid solubility for Nb. The increase in Nb in the liquid phase increases the composition supercooling and heteronucleation at the solidification front, which accounts for refining the lamellar colony. Room temperature compressive testing showed that the compressive strength and the strain increased when the Ta content increased up to 0.8% and then decreased. Improvement of the compressive properties resulted from the grain boundary strengthening and their decrease induced by more content of the B2 phase. Tensile properties, at elevated temperature, were improved with testing temperature increasing from 750 to 950°C, because solid solution strengthening is a major influence factor. |
| first_indexed | 2024-03-07T18:14:02Z |
| format | Article |
| id | doaj.art-9dabc28dea1745328cac3ea659f6a4ea |
| institution | Directory Open Access Journal |
| issn | 2639-5274 |
| language | English |
| last_indexed | 2024-03-07T18:14:02Z |
| publishDate | 2019-01-01 |
| publisher | American Association for the Advancement of Science (AAAS) |
| record_format | Article |
| series | Research |
| spelling | doaj.art-9dabc28dea1745328cac3ea659f6a4ea2024-03-02T07:38:01ZengAmerican Association for the Advancement of Science (AAAS)Research2639-52742019-01-01201910.34133/2019/5143179Effects of Tantalum on Microstructure Evolution and Mechanical Properties of High-Nb TiAl Alloys Reinforced by Ti2AlCHongze Fang0Ruirun Chen1Yong Yang2Yanqing Su3Hongsheng Ding4Jingjie Guo5National Key Laboratory for Precision Hot Processing of Metals, Harbin Institute of Technology, 150001, ChinaNational Key Laboratory for Precision Hot Processing of Metals, Harbin Institute of Technology, 150001, China; State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, 150001, ChinaNational Key Laboratory for Precision Hot Processing of Metals, Harbin Institute of Technology, 150001, ChinaNational Key Laboratory for Precision Hot Processing of Metals, Harbin Institute of Technology, 150001, ChinaNational Key Laboratory for Precision Hot Processing of Metals, Harbin Institute of Technology, 150001, ChinaNational Key Laboratory for Precision Hot Processing of Metals, Harbin Institute of Technology, 150001, ChinaExperiments have been carried out to study the relationship between the addition of tantalum and microstructure, especially the formation of the B2 phase in lamellar colonies. The mechanical properties, with different contents of Ta, were also measured. Ti46Al8Nb2.6CxTa alloys were prepared by casting with the content of Ta varying from zero to 1.0 at.%. Experimental results show that the B2 phase forms in lamellar colonies with the addition of Ta, and its content increases when the content of Ta increases. Meanwhile, the γ phase decreases and the lattice parameter of the α2 phase increases. The size of the lamellar colony decreased from 29.9 to 21.6 μm. Ta dissolves into Ti2AlC by substitution, and its solubility is more than 1.1% tested by EDS. Nb, which is necessary for the formation of the B2 phase, comes from two aspects. The first is that Ta dissolves into the Ti2AlC and partly replaces the Nb atom and the second is the decrease in the γ phase because it has higher solid solubility for Nb. The increase in Nb in the liquid phase increases the composition supercooling and heteronucleation at the solidification front, which accounts for refining the lamellar colony. Room temperature compressive testing showed that the compressive strength and the strain increased when the Ta content increased up to 0.8% and then decreased. Improvement of the compressive properties resulted from the grain boundary strengthening and their decrease induced by more content of the B2 phase. Tensile properties, at elevated temperature, were improved with testing temperature increasing from 750 to 950°C, because solid solution strengthening is a major influence factor.http://dx.doi.org/10.34133/2019/5143179 |
| spellingShingle | Hongze Fang Ruirun Chen Yong Yang Yanqing Su Hongsheng Ding Jingjie Guo Effects of Tantalum on Microstructure Evolution and Mechanical Properties of High-Nb TiAl Alloys Reinforced by Ti2AlC Research |
| title | Effects of Tantalum on Microstructure Evolution and Mechanical Properties of High-Nb TiAl Alloys Reinforced by Ti2AlC |
| title_full | Effects of Tantalum on Microstructure Evolution and Mechanical Properties of High-Nb TiAl Alloys Reinforced by Ti2AlC |
| title_fullStr | Effects of Tantalum on Microstructure Evolution and Mechanical Properties of High-Nb TiAl Alloys Reinforced by Ti2AlC |
| title_full_unstemmed | Effects of Tantalum on Microstructure Evolution and Mechanical Properties of High-Nb TiAl Alloys Reinforced by Ti2AlC |
| title_short | Effects of Tantalum on Microstructure Evolution and Mechanical Properties of High-Nb TiAl Alloys Reinforced by Ti2AlC |
| title_sort | effects of tantalum on microstructure evolution and mechanical properties of high nb tial alloys reinforced by ti2alc |
| url | http://dx.doi.org/10.34133/2019/5143179 |
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