Twinning-induced dislocation and coordinated deformation behavior of a high-Nb TiAl alloy during high-cycle fatigue

Xu, Xuesong; Ding, Hongsheng; Huang, Haitao; He, Liang; Ramanujan, R.V.; Chen, Ruirun; Guo, Jingjie; Fu, Haipeng

doi:10.1016/j.ijfatigue.2023.107597

Cited by 9 publications

(2 citation statements)

References 66 publications

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“…The material will become an important alternative structural material for the aerospace industry, especially the lightweight high-temperature structural material for the new generation of supersonic aircraft, thereby reducing the weight of aviation engines and improving efficiency. However, the working temperature of aeroengine blades and turbofan engines made of TiAl alloy materials is around 650 • C [1][2][3]. For this situation to be changed, researchers have improved the properties of TiAl alloy by adapting process parameters and annealing techniques, and adding different alloying elements such as Cr, Mn, W, Mo, Si, B, C, Ta, and Nb.…”

Section: Introductionmentioning

confidence: 99%

Enhancement of Microstructure and Mechanical Properties of High Nb-TiAl Alloys Prepared Using Laser Additive Manufacturing by Annealing Treatment

Liang,

Liu,

Wang

et al. 2023

Metals

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The microstructure, phase composition, hardness, and tensile properties of the Ti-48Al-2Cr-5Nb alloy have been systematically investigated using laser additive manufacturing technology. Results indicate that both the as-deposited and annealed microstructures contain both the α2 (Ti3Al) and γ (TiAl) phases. As the annealing temperature increased, the structure changed significantly from a large block structure to a fine equiaxed structure and finally to a large lamellar structure. Nevertheless, the amount and distribution of precipitation of α2 phase are obviously different, especially during the annealing at 1260 °C, where the fine α2 phases are evenly distributed on the γ phase matrix. The hardness value of the as-deposited sample is the highest, with a HV value of 484 at the room temperature, while the hardness value of the annealed sample at 1260 °C is the smallest, with a HV value of 344. An annealed sample at 1260 °C exhibits the highest tensile strength and elongation at room temperature, with values of 598 MPa and 2.1%, respectively. These values are increased by 1.15 times and 1.4 times compared to the as-deposited sample (519 MPa, 1.5%).

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Section: Introductionmentioning

confidence: 99%

Enhancement of Microstructure and Mechanical Properties of High Nb-TiAl Alloys Prepared Using Laser Additive Manufacturing by Annealing Treatment

Liang,

Liu,

Wang

et al. 2023

Metals

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“…In fatigue and creep experiments of the TiAl alloys below the T eu , the pressure can significantly accelerate the service decomposition of the α 2 phase. The α 2 → γ phase transformation occurs in traditional the TiAl alloys in different service conditions, but the morphological and orientation relationship characteristics of these phase transformations are considerably different in different modes [ 27 , 28 , 29 , 30 ]. There are few studies on the microstructure instability and phase transformation of the TiAl alloy with high-stress stored energy at service temperature.…”

Section: Introductionmentioning

confidence: 99%

Microstructure Evolution of the Ti-46Al-8Nb-2.5V Alloy during Hot Compression and Subsequent Annealing at 900 °C

Cao,

Li,

et al. 2023

Materials

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TiAl alloys are high-temperature structural materials with excellent comprehensive properties, and their ideal service temperature range is about 700–950 °C. High-Nb containing the Ti-46Al-8Nb-2.5V alloy was subjected to hot compression and subsequent annealing at 900 °C. During hot compression, work-hardening and strain-softening occurred. The peak stresses during compression are positively correlated with the compressive strain rates and negatively correlated with the compression temperatures. The α2 phase exhibited a typical (0001)α2 basal plane texture after hot compression, while the β0 and γ phases did not show a typical strong texture. Subsequent annealing at 900 °C of the hot-compressed samples resulted in significant phase transformations, specifically the α2 → γ and β0 → γ phase transformations. After 30 min of annealing, the volume fraction of the α2 phase decreased from 39.0% to 4.6%. The microstructure characteristics and phase fraction after 60 min of annealing were similar to those after 30 min. According to the calculation of Miller indexes and texture evolution during annealing, the α2 → γ phase transformation did not follow the Blackburn orientation relationship. Multiple crystal-oriented α2 phases with nanoscale widths (20~100 nm) precipitate within the γ phase during the annealing process, which means the occurrence of γ → α2 phase transformation. Still, the γ → α2 phase transformation follows the Blackburn orientation relationship.

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Advanced TiAl Based Alloys: From Polycrystals to Polysynthetic Twinned Single Crystals

Zhao,

Chu,

et al. 2024

Adv Funct Materials

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TiAl alloys stand out for low density, high specific strength, and excellent creep resistance, making them promising for high‐temperature aerospace applications. However, traditional TiAl alloys suffer from poor room‐temperature ductility and low service temperature that limit their critical applications in aerospace structures. To address these issues, research has focused on improving the mechanical properties of TiAl alloys through alloying and microstructural design. After decades of effort, the evolution of TiAl alloys has progressed from polycrystalline TiAl to high‐performance polysynthetic twinned (PST) TiAl single crystals. The well‐aligned PST TiAl single crystals enriched with Nb enable an excellent combination of strength and ductility, significantly outperforming polycrystalline TiAl alloys. This review summarizes recent progress on TiAl alloys, particularly focusing on newly developed PST single crystals. First, the development history of TiAl alloys is overviewed; then their crystal structures, phase diagrams, and typical microstructures are systematically discussed, along with the design strategies based on alloying elements. Additionally, recent advances in TiAl columnar crystals, which are between polycrystals and single crystals, are reviewed. Subsequently, the mechanical anisotropy, preparation methods, and superior mechanical properties of the PST single crystals are analyzed in detail. The final remark highlights the future development and application prospects of TiAl alloys.

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Twinning-induced dislocation and coordinated deformation behavior of a high-Nb TiAl alloy during high-cycle fatigue

Cited by 9 publications

References 66 publications

Enhancement of Microstructure and Mechanical Properties of High Nb-TiAl Alloys Prepared Using Laser Additive Manufacturing by Annealing Treatment

Enhancement of Microstructure and Mechanical Properties of High Nb-TiAl Alloys Prepared Using Laser Additive Manufacturing by Annealing Treatment

Microstructure Evolution of the Ti-46Al-8Nb-2.5V Alloy during Hot Compression and Subsequent Annealing at 900 °C

Advanced TiAl Based Alloys: From Polycrystals to Polysynthetic Twinned Single Crystals

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