The Effect of Heat Treatment on the Microstructure and Mechanical Properties of Powder Metallurgy Ti-48Al Alloy
Abstract
:1. Introduction
2. Materials and Methods
3. Results
3.1. Microstructure and Properties of Extruded Ti-48Al Alloy
3.2. Effect of Heat Treatment Temperature on the Microstructure and Mechanical Properties of Ti-48Al Alloy
3.3. Effect of Cooling Method on Microstructure and Properties
3.4. Effect of Holding Time on Microstructure and Properties
4. Discussion
5. Conclusions
- (1)
- The heat treatment temperature determines the type of microstructure, while the cooling rate determines the width of the lamellae. As the heat treatment temperature increases from the two-phase region to the α single-phase region, the microstructure transitions from dual-phase to near-lamellar. The strength of the alloy initially increases and then decreases, which is determined by both the number of lamellae and the grain size. With rapid cooling (water cooling), non-diffusive type blocky phase transformations occur, while slower cooling (air cooling) gradually forms α2/γ lamellar colonies.
- (2)
- The heat treatment process identified as suitable for powder Ti-48Al alloy was 1340 °C, holding for 5 min, followed by air cooling. Under these conditions, the microstructure of the alloy as near-lamellar, consisting of lamellar colonies (about 50 μm) and a small amount of fine γ equiaxed grains (about 10 μm). The room temperature tensile strength was 784 MPa, and the yield strength was 763 MPa, which represents improvements of 17.0% and 38.7%, respectively, compared to the extruded state.
Author Contributions
Funding
Data Availability Statement
Conflicts of Interest
References
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Temperature/°C | 1300 | 1320 | 1340 | 1360 |
Equiaxial grain size/μm | 12 | 11 | 8 | - |
Lamellar colonies size/μm | 18 | 28 | 57 | 107 |
Lamellar interspacing/nm | 468 | 476 | 445 | 701 |
Lamellar colonies ratio/% | 64 | 79 | 92 | 100 |
Holding Time/°C | Equiaxial Grain Size/μm | Lamellar Colonies Size/μm | Lamellar Colonies Ratio/% |
---|---|---|---|
3 | 10 | 31 | 81 |
5 | 8 | 43 | 88 |
10 | 8 | 57 | 92 |
20 | 8 | 75 | 94 |
Alloy Composition | Process | Tensile Strength (MPa) | Yield Strength (MPa) | Elongation (%) |
---|---|---|---|---|
Ti-48Al (this work) | HT | 784 | 763 | 0.8 |
Ti-48Al-2Cr-2Nb [9] | CHT | 697 | - | 2.1 |
Ti-48Al-2Cr-2Nb [24] | Forging | 474 | 357 | 1.64 |
Ti-48Al-2Cr-2Nb [25] | HT | 477 | 577 | 1.2 |
Ti-44.5Al-1.0Cr-2.5V-2.0Mo [26] | HE | 540 | 481 | - |
Ti-48Al-2Cr-2Nb [2] | EBM | 855 | - | 2.1 |
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Yan, M.; Zhang, H.; Yang, F.; Gui, Y.; Han, Z.; Fu, H. The Effect of Heat Treatment on the Microstructure and Mechanical Properties of Powder Metallurgy Ti-48Al Alloy. Metals 2024, 14, 661. https://doi.org/10.3390/met14060661
Yan M, Zhang H, Yang F, Gui Y, Han Z, Fu H. The Effect of Heat Treatment on the Microstructure and Mechanical Properties of Powder Metallurgy Ti-48Al Alloy. Metals. 2024; 14(6):661. https://doi.org/10.3390/met14060661
Chicago/Turabian StyleYan, Mengjie, Hongtao Zhang, Fang Yang, Yunwei Gui, Zhijie Han, and Huadong Fu. 2024. "The Effect of Heat Treatment on the Microstructure and Mechanical Properties of Powder Metallurgy Ti-48Al Alloy" Metals 14, no. 6: 661. https://doi.org/10.3390/met14060661