Microstructure characterization, mechanical properties and toughening mechanism of TiB 2 -containing conventional cast TiAl-based alloy

Han, Jianchao; Xiao, Shulong; Tian, Jing; Chen, Yuyong; Xu, Lijuan; Wang, Xiaopeng; Jia, Yaoyao; Rahoma, H.K.S.; Du, Zhongjie; Cao, Shouzhen

doi:10.1016/j.msea.2015.07.092

Cited by 31 publications

(9 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Microstructure of TiAl alloys significantly affects the high-temperature properties. The two-phase ( γ + α 2 ) alloys usually have better mechanical properties than single-phase γ alloys or α 2 alloys, because the uniformly distributed α 2 phase is acting as the reinforcement of γ phase [9,10], including the mechanisms of reinforcement of γ phase through α 2 interfaces [11,12]. TiAl alloys with such microstructure, which are commonly known as γ -TiAl base alloys, generally possess the best combination of room-temperature toughness and high-temperature strength [13].…”

Section: Introductionmentioning

confidence: 99%

Creep behaviour of equiaxed fine-grain γ-TiAl-based alloy prepared by powder metallurgy

Duan

Han

Song

et al. 2020

Materials Science and Technology

View full text Add to dashboard Cite

In this study, γ-TiAl-based alloy with chemical composition of Ti–45Al–5Nb (in at.-%) fabricated by powder metallurgy method was crept at 700°C under 200–500 MPa. The creep properties and the microstructure after creep tests were investigated. The results showed that the γ-TiAl-based alloy was composed of equiaxed γ-TiAl grains and α2-Ti3Al grains with average sizes of 1.4 and 0.5 μm, respectively. The creep resistance deteriorated generally with increased applied stresses. The typical intergranular fracture characteristics were observed though the grains were small. The calculated stress exponent and activation energy revealed the main creep mechanism of grain boundary sliding. Furthermore, twinning and dynamic recrystallisation also led to the creep deformation.

show abstract

Section: Introductionmentioning

confidence: 99%

Creep behaviour of equiaxed fine-grain γ-TiAl-based alloy prepared by powder metallurgy

Duan

Han

Song

et al. 2020

Materials Science and Technology

View full text Add to dashboard Cite

show abstract

“…Studies have indicated that the fracture toughness of TiAl-based alloys results from various factors including the microstructure types, lamellar orientation, colony size, interlamellar spacing, and internal stress. [18][19][20][21][22][23][24][25][26] The fully lamellar (FL) microstructure generally exhibits the highest fracture toughness among all the microstructure types. [18] The fracture resistance of the trans-lamellar mode is higher than that of the inter-lamellar mode.…”

Section: Introductionmentioning

confidence: 99%

“…[18] The fracture resistance of the trans-lamellar mode is higher than that of the inter-lamellar mode. [23] Both finer interlamellar spacing and higher internal stress improve fracture toughness. [23,25] However, limited attention has been paid to the fracture toughness and fracture behavior of TiAl-based alloys with superior deformation twinning ability.…”

Section: Introductionmentioning

confidence: 99%

“…[23] Both finer interlamellar spacing and higher internal stress improve fracture toughness. [23,25] However, limited attention has been paid to the fracture toughness and fracture behavior of TiAl-based alloys with superior deformation twinning ability. To address this gap and on basis of previous researches, [15,27] a series of investigations (including microstructure characterization, fracture toughness measurement, and observation of crack propagation path) were conducted on two samples fabricated by the CCHT method, as well as the continuous casting (C. C.) alloy, which was used for comparison in this research.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Improved Fracture Toughness of Polycrystalline γ‐TiAl‐Based Intermetallic Alloys with a Favorable Deformation Mechanism of Twinning

et al. 2022

View full text Add to dashboard Cite

High-density deformation nanotwins markedly strengthen TiAl-based alloys; however, the improvement in strength generally leads to a reduction in fracture toughness for most structural materials. It is, therefore, necessary to investigate the benefits of high-density deformation nanotwins for the improvement in fracture toughness of TiAl-based alloys. Herein, the fracture toughness of two Ti-45.5Al-4Cr-2.5Nb alloys with a favorable deformation mechanism of twinning (prepared by annealing the continuous casting (C. C.) alloy at 1250 C and 1270 C for different durations, respectively) is investigated and compared with that of the unannealed continuous casting (C. C.) alloy, in terms of room-temperature (RT) tensile properties and microstructures. It is found that the two heattreated Ti-45.5Al-4Cr-2.5Nb alloys exhibits a higher fracture toughness than the C. C. alloy. Shear ligaments and slip bands are the main toughening mechanisms for the two heat-treated alloys; their generation is closely related to the enhancement in the plastic deformability of lamellar structures. In addition, the increase in (B2 þ γ)-coupled structures is found to impose a negative effect on the toughening of the investigated alloys. High-density deformation nanotwins favor the improvement in fracture toughness of TiAl-based alloys by improving their fracture strength and plastic deformability, while decreasing their workhardening exponent.

show abstract

“…Due to the low density, high specific strength, elastic modulus, and oxidation resistance at high temperatures, γ-TiAl-based alloys have been considered as strong candidates for high-temperature structural applications in aerospace and automotive industries [ 1 , 2 , 3 ]. However, the poor hot workability and low room temperature ductility severely restrict their application [ 4 , 5 ].…”

Section: Introductionmentioning

confidence: 99%

Microstructural Characterization of Melt Extracted High-Nb-Containing TiAl-Based Fiber

Zhang

Chen³

et al. 2017

Materials

Self Cite

View full text Add to dashboard Cite

Abstract:The microstructure of melt extracted Ti-44Al-8Nb-0.2W-0.2B-1.5Si fiber were investigated. When the rotation speed increased from 2000 to 2600 r/min, the appearance of the wire was uniform with no Rayleigh-wave default. The structure was mainly composed of fine α 2 (α) phase dendritic crystal and a second phase between dendrite arms and grain boundaries. The precipitated second phases were confirmed to be Ti 5 Si 3 from the eutectic reaction L→Ti 5 Si 3 + α and TiB. As the lower content of Si and higher cooling rate, a divorced eutectic microstructure was obtained. Segregation of Ti, Nb, B, Si, and Al occurred during rapid solidification.

show abstract

Microstructure characterization, mechanical properties and toughening mechanism of TiB 2 -containing conventional cast TiAl-based alloy

Cited by 31 publications

References 49 publications

Creep behaviour of equiaxed fine-grain γ-TiAl-based alloy prepared by powder metallurgy

Creep behaviour of equiaxed fine-grain γ-TiAl-based alloy prepared by powder metallurgy

Improved Fracture Toughness of Polycrystalline γ‐TiAl‐Based Intermetallic Alloys with a Favorable Deformation Mechanism of Twinning

Microstructural Characterization of Melt Extracted High-Nb-Containing TiAl-Based Fiber

Contact Info

Product

Resources

About