The Micro Crack Nucleation Rule and Fracture Behavior of Titanium Aluminum Alloy

Study on tensile fracture behavior of TiAl alloy by means of the macro fracture theory and micro dislocation block theory. A quantitative analysis method of micro crack nucleation and crack mechanism for TiAl alloy is performed with the help of the dislocation distribution model, and is based on the strain energy density theory and criterion, a crack criterion of TiAl alloy instability is established. The experimental results confirmed that the dislocation model and S criterion on tensile fracture behavior of TiAl alloys are effective.

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Tensile Fracture Characteristics of a Single Crystal Nickel-Based Superalloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.922.819 ◽

2014 ◽

Vol 922 ◽

pp. 819-825

Author(s):

Dan Wu ◽

Li Xi Tian ◽

Chao Li Ma

Keyword(s):

Single Crystal ◽

Fracture Behavior ◽

Room Temperature ◽

Crack Nucleation ◽

Tensile Fracture ◽

Void Coalescence ◽

Fracture Characteristics ◽

Final Fracture ◽

Nickel Based Superalloy ◽

Fracture Area

Tensile fracture behavior of a single crystal nickel-based superalloy with different orientations and temperatures was studied. The tensile fracture surfaces and microstructure were analyzed by field emission scanning electron microscope (FE-SEM). The results showed that, generally, this single crystal nickel-based superalloy exhibited obvious tensile anisotropy. Under the condition of room temperature, the different areas of crack nucleation, propagation and final fracture area were clearly observed and varied greatly in different orientations. At elevated temperature, the fracture surface presented mixed characteristics of holes and dimples and its fracture was dominated by micro-void coalescence. Fracture mechanism was discussed.

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THE EFFECT OF HIGH TEMPERATURE CORROSION ON MECHANICAL BEHAVIOR OF A GAMMA-TiAl ALLOY

International Journal of Modern Physics B ◽

10.1142/s0217979210065945 ◽

2010 ◽

Vol 24 (15n16) ◽

pp. 2970-2975 ◽

Cited By ~ 1

Author(s):

WENYUE ZHAO ◽

YUE MA ◽

SHENGKAI GONG

Keyword(s):

High Temperature ◽

Fracture Behavior ◽

Tial Alloy ◽

Crack Nucleation ◽

High Temperature Corrosion ◽

Bending Tests ◽

Three Point Bending ◽

Salt Corrosion ◽

Corrosion Pits ◽

Bending Fracture

The mechanical properties of Ti -48 Al -2 Cr -2 Nb alloy were discussed after the high temperature corrosion tests carried out with salt mixture of 75wt. % Na 2 SO 4 and 25wt. % NaCl at 800°C. The microstructure of the alloy after corrosion was observed by SEM and the fracture behavior of the corroded and uncorroded alloys was investigated by means of the three-point bending tests. It has been shown that the corrosion path was mainly along the lamellar structure and rough surface with a large number of corrosion pits formed during the high temperature corrosion. The experimental results also indicated that the bearing capacity of bending fracture descended evidently due to the molten salt corrosion at high temperature, which only had remarkable effects on the surface state of the alloy. The microcracks inside the alloy always propagated along the phase interfaces and grain boundaries while the corrosion pits on salt-deposited surface became the main crack initiation location in corroded alloy. The stress concentration caused by corrosion was considered as the essential reason of the property reduction, which decreased the energy barrier of crack nucleation and shortened the incubation period.

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Tensile Fracture Behavior of Cu/Al Butt Friction Stir Welding: Role of Interface Morphology

Journal of Materials Engineering and Performance ◽

10.1007/s11665-021-06281-3 ◽

2021 ◽

Author(s):

Tran Hung Tra ◽

Masakazu Okazaki ◽

Duong Dinh Hao

Keyword(s):

Friction Stir Welding ◽

Fracture Behavior ◽

Tensile Fracture ◽

Interface Morphology ◽

Friction Stir

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Dynamic Effect on Impact Tensile Fracture Behavior of PMMA Resin

Journal of the Society of Materials Science Japan ◽

10.2472/jsms.57.374 ◽

2008 ◽

Vol 57 (4) ◽

pp. 374-379 ◽

Cited By ~ 1

Author(s):

Kazuo ARAKAWA ◽

Masaru KATO ◽

Toshio MADA ◽

Mitsugu TODO

Keyword(s):

Fracture Behavior ◽

Dynamic Effect ◽

Tensile Fracture ◽

Pmma Resin

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Ductile TiAl alloy with a Widmanstätten lamellar structure formed by rapid heating

Journal of Materials Research ◽

10.1557/jmr.2008.0138 ◽

2008 ◽

Vol 23 (4) ◽

pp. 949-953 ◽

Cited By ~ 5

Author(s):

J.P. Cui ◽

M.L. Sui ◽

Y.Y. Cui ◽

D.X. Li

Keyword(s):

Electric Current ◽

Lamellar Structure ◽

Tial Alloy ◽

Rapid Heating ◽

Pulse Treatment ◽

Electric Current Pulse ◽

Microstructural Refinement ◽

Tial Alloys ◽

Refinement Mechanism ◽

Fully Lamellar

Instead of conventional grain-refinement treatments for improving the ductility of fully lamellar TiAl alloys, multiorientational, lamellar, subcolony refinement with good ductility has been achieved simply by using an electric-current pulse treatment. The microstructural refinement mechanism is attributed to the transformation on heating of γ laths in the prior large-grain lamellar structure to Widmanstätten α in several orientations, which on subsequent cooling forms lamellar structure colonies in multiple orientations. This kind of refined multiple-colony lamellar structure was found to enhance the ductility of the TiAl alloy.

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The Microstructural Evolution, Tensile Properties, and Phase Hardness of a TiAl Alloy with a High Content of the β Phase

Materials ◽

10.3390/ma12172757 ◽

2019 ◽

Vol 12 (17) ◽

pp. 2757 ◽

Cited By ~ 3

Author(s):

Ning Cui ◽

Qianqian Wu ◽

Zhiyuan Yan ◽

Haitao Zhou ◽

Xiaopeng Wang

Keyword(s):

Tensile Properties ◽

Room Temperature ◽

Tial Alloy ◽

Microstructural Analysis ◽

Phase Content ◽

Tial Alloys ◽

Β Phase ◽

Room Temperature Ductility ◽

One Step ◽

Equiaxed Grains

In this paper, the microstructure, deformability, tensile properties, and phase hardness of the Ti–43Al–2Cr–0.7Mo–0.1Y alloy with a high β phase content were investigated. Microstructural analysis showed that the β phase precipitated not only at the colony boundaries but also inside the lamellae due to its high content. A high-quality forging stock was prepared through one-step noncanned forging. The total deformation reached above 80%, suggesting that the alloy has good hot deformability compared to other TiAl alloys. The deformed microstructure was composed of fine and equiaxed grains due to dynamic recrystallization. The high β phase content was shown to contribute to the decomposition of the initial coarse lamellae. Tensile testing showed that the alloy has good room-temperature ductility, even if the β phase content reaches above 20%. This is inconsistent with a previous study that showed that a large amount of the hard β phase is detrimental to the room-temperature ductility of TiAl alloys. Nanoindentation testing showed that the hardness of the β phase in the current alloy is about 6.3 GPa, which is much lower than that in the Nb-containing TiAl alloys. Low hardness benefits the compatible deformation among various phases, which could be the main reason for the alloy’s good room-temperature ductility. Additionally, the influence of various β stabilizers on the hardness of the β phase was also studied. The β phase containing Nb had the highest hardness, whereas the β phase containing Cr had the lowest hardness.

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The Deformation Characteristics, Fracture Behavior and Strengthening-Toughening Mechanisms of Laminated Metal Composites: A Review

Metals ◽

10.3390/met10010004 ◽

2019 ◽

Vol 10 (1) ◽

pp. 4 ◽

Cited By ~ 1

Author(s):

Kuan Gao ◽

Xin Zhang ◽

Baoxi Liu ◽

Jining He ◽

Jianhang Feng ◽

...

Keyword(s):

Mechanical Properties ◽

Metal Matrix Composites ◽

Metal Matrix ◽

Fracture Behavior ◽

Tensile Fracture ◽

Matrix Composites ◽

Deformation Characteristics ◽

Toughening Mechanisms ◽

Metal Composites ◽

Fracture Elongation

Multilayer metal composites have great application prospects in automobiles, ships, aircraft and other manufacturing industries, which reveal their superior strength, toughness, ductility, fatigue lifetime, superplasticity and formability. This paper presents the various mechanical properties, deformation characteristics and strengthening–toughening mechanisms of laminated metal matrix composites during the loading and deformation process, and that super-high mechanical properties can be obtained by adjusting the fabrication process and structure parameters. In the macroscale, the interface bonding status and layer thickness can effectively affect the fracture, impact toughness and tensile fracture elongation of laminated metal matrix composites, and the ductility and toughness cannot be fitting to the rule of mixture (ROM). However, the elastic properties, yield strength and ultimate strength basically follow the rule of mixture. In the microscale, the mechanical properties, deformation characteristics, fracture behavior and toughening mechanisms of laminated composites reveal the obvious size effect.

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Mechanical and Fractographical Characterization of Extruded Al-Mg-Si-Zr Alloys

MATEC Web of Conferences ◽

10.1051/matecconf/201818802017 ◽

2018 ◽

Vol 188 ◽

pp. 02017

Author(s):

Fulya Kahrıman ◽

Muzaffer Zeren

Keyword(s):

Fracture Behavior ◽

Direct Chill ◽

Grain Structure ◽

Tensile Fracture ◽

Casting Method ◽

Cross Sectional ◽

Fracture Surfaces ◽

The Matrix ◽

Zr Alloys

In this study, the chemical composition of Al-0.8Mg-0.8Si alloys was modified with the addition of 0.1 and 0.2 wt.-% Zr. The billets were manufactured by direct chill casting method, homogenized at 560 °C for 6h and then extruded in order to obtain profiles having hollow and circular sections. Recrystallization layer (shell) became narrower due to the addition of Zr. This was attributed to the formation of very fine precipitates (Al3Zr) within the matrix. The mechanical properties showed that both yield and tensile strengths increased as a function of Zr content. Tensile fracture surfaces were examined by scanning electron microscope and the fractographs reflected the effect of grain structure on the fracture behavior of studied alloys. All fracture surfaces indicated typical dimple ruptures, however, the size of dimples were observed as finer structures as a function of Zr content. As seen in cross-sectional graphs, as the Zr content increased the grain structure was refined due to Al3Zr precipitates. These fine precipitates caused the formation of fine and shallow dimples under loading.

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