Abstract
A TNM alloy ingot was fabricated with powder hot isostatic pressing (P-HIP) and short-time exposure treatment conducted at 750–1050◦ C for 2–5 h. The tensile mechanical properties were investigated at room temperature and 800◦ C. The results revealed that a fully lamellar microstructure of P-HIPed TNM alloy with only 0.3 vol.% β0 phase could be obtained by hot isostatic pressing at 1260◦ C, under the pressure of 170 MPa, held for 4 h. When the exposure temperature was below 850◦ C, the α2 lamellae were transformed into nano-scaled (α2 + γ) lamellae (i.e., the α2 →α2 + γ transformation). With increases in the exposure temperature, the β0 phase began to precipitate within the α2 lamellae (α2 →β0 transformation) at 950◦ C. The α2 →γ and the α2 →β0 transformation both happened at 950–1050◦ C, and the higher exposure temperature accelerated the diffusion of Mo and facilitated the α2 →β0 transformation. The yield strength and elongation at RT and 800◦ C were both improved after short-time high-temperature exposure treatment. The uniform distribution and nano-scaled interfacial β0 phase provided precipitation strengthening and were not harmful to the elongation.
Original language | English |
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Article number | 1720 |
Journal | Metals |
Volume | 11 |
Issue number | 11 |
DOIs | |
State | Published - Nov 2021 |
Keywords
- Hot isostatic pressing
- Microstructure
- Tensile properties
- Thermal stability
- TiAl-based alloys