scholarly journals In-Situ SEM Observation on Fracture Behavior of Titanium Alloys with Different Slow-Diffusing β Stabilizing Elements

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1848
Author(s):  
Wenjing Zhang ◽  
Haofeng Xie ◽  
Songxiao Hui ◽  
Wenjun Ye ◽  
Yang Yu ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Tensile Deformation ◽  
Three Dimensional ◽  
Atom Probe ◽  
Β Phase ◽  
Phase Size ◽  
Bcc Structure ◽  
Hcp Structure

The fracture-behaviors of two Ti-Al-Sn-Zr-Mo-Nb-W-Si alloys with different slow-diffusing β stabilizing elements (Mo, W) were investigated through in-situ tensile testing at 650 °C via scanning electron microscopy. These alloys have two phases: the α phase with hcp-structure (a = 0.295 nm, c = 0.468 nm) and the β phase with bcc-structure (a = 0.332 nm). Three-dimensional atom probe (3DAP) results show that Mo and W mainly dissolve in the β phase, and they tend to cluster near the α/β phase boundary. Adding more slow-diffusing β stabilizing elements can improve the ultimate tensile strength and elongation of the alloy at 650 °C. During tensile deformation at 650 °C, microvoids mainly initiate at α/β interfaces. With increases in the contents of Mo and W, the β phase content increases and the average phase size decreases, which together have excellent accommodative deformation capability and will inhibit the microvoids’ nucleation along the interface. In addition, the segregation of Mo and W near the α/β interface can reduce the diffusion coefficient of the interface and inhibit the growth of microvoids along the interface, which are both helpful to improve the ultimate tensile strength and plasticity.

scholarly journals Study on Microstructure and In Situ Tensile Deformation Behavior of Fe-25Mn-xAl-8Ni-C Alloy Prepared by Vacuum Arc Melting

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 814
Author(s):  
Yaping Bai ◽  
Meng Li ◽  
Chao Cheng ◽  
Jianping Li ◽  
Yongchun Guo ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Deformation Behavior ◽  
Tensile Deformation ◽  
Austenite Phase ◽  
Vacuum Arc ◽  
Al Content ◽  
Arc Melting ◽  
Vacuum Arc Melting ◽  
Tensile Deformation Behavior

In this study, Fe-25Mn-xAl-8Ni-C alloys (x = 10 wt.%, 11 wt.%, 12 wt.%, 13 wt.%) were prepared by a vacuum arc melting method, and the microstructure of this series of alloys and the in situ tensile deformation behavior were studied. The results showed that Fe-25Mn-xAl-8Ni-C alloys mainly contained austenite phase with a small amount of NiAl compound. With the content of Al increasing, the amount of austenite decreased while the amount of NiAl compound increased. When the Al content increased to 12 wt.%, the interface between austenite and NiAl compound and austenitic internal started to precipitate k-carbide phase. In situ tensile results also showed that as the content of Al increased, the alloy elongation decreased gradually, and the tensile strength first increased and then decreased. When the Al content was up to 11 wt.%, the elongation and tensile strength were 2.6% and 702.5 MPa, respectively; the results of in situ tensile dynamic observations show that during the process of stretching, austenite deformed first, and crack initiation mainly occurred at the interface between austenite and NiAl compound, and propagated along the interface, resulting in fracture of the alloy.

Tensile Properties and Fracture Behavior of SiCp/AC4CH Composite at Loading Velocities of up to 10m/s

2004 ◽  
Vol 449-452 ◽  
pp. 305-308
Author(s):  
Lei Wang ◽  
Toshiro Kobayashi ◽  
Chun Ming Liu
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Tensile Test ◽  
Strain Rate ◽  
Fracture Behavior ◽  
Tensile Deformation ◽  
Optical Microscope ◽  
Fracture Elongation ◽  
Before And After

Tensile test at loading velocities up to 10 m·s-1(strain rate up to 3.2x102s-1) was carried out forr SiCp/AC4CH composite and AC4CH alloy. The microstructure of the composite before and after tensile deformation was carefully examined with both optical microscope and SEM. The experimental results demonstrated that the ultimate tensile strength (UTS) and yield strength (YS) increase with increasing loading velocity up to 10 m·s-1. Comparing with AC4CH alloy, the fracture elongation of the composite is sensitivity with the increasing strain rate. The YS of both the composite and AC4CH alloy shows more sensitive than that of the UTS with the increasing strain rate, especially in the range of strain rate higher than 102s-1.

Effect of the Linear Electromagnetic Stirring on Microstructure and Properties of Cu-10%Nb Alloys

2013 ◽  
Vol 395-396 ◽  
pp. 205-208
Author(s):  
Lin Zhang ◽  
En Gang Wang ◽  
Xiao Wei Zuo ◽  
Wen Bin Wang ◽  
Ji Cheng He
Keyword(s):  
Electrical Conductivity ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Lognormal Distribution ◽  
Electromagnetic Stirring ◽  
Microstructure And Properties ◽  
Homogenous Distribution ◽  
Phase Size

Cu-10%Nb alloys were solidified with or without electromagnetic stirring. The effect of electromagnetic stirring (EMS) on the distribution of Nb particles in solidified Cu-10%Nb ingots and the performance of its deformed wires were studied. The 300A/16Hz EMS has refined the microstructure of Cu-10%Nb alloy, with smaller phase size and larger amount, and is benefit to the homogenous distribution of Nb-rich phases. The fitted lognormal distribution of Nb phase size in case without or with EMS is compared, and the EMS case has the higher frequency percentage in the range of smaller size for both the solidified ingot and the deformed wire. Cu-10%Nb wires in EMS case have a less value of electrical conductivity and a considerably higher ultimate tensile strength compared with that without EMS.

Influence of Heat Treatment on Microstructure and Tensile Property of Ti-5Al-5Mo-5V-3Cr-1Fe Alloy

2013 ◽  
Vol 365-366 ◽  
pp. 1003-1006
Author(s):  
Yan Yan Fu ◽  
Song Xiao Hui ◽  
Wen Jun Ye ◽  
Xu Jun Mi
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Tensile Property ◽  
Aging Temperature ◽  
Aging Treatment ◽  
Minimum Level ◽  
Β Phase ◽  
Α Phase

The effect of solution and aging temperatures on microstructure and tensile property of Ti-5Al-5Mo-5V-3Cr-1Fe Alloy was investigated. The results showed that the tensile strength lowered, when the solution and aging temperature rose respectively. The alloy with different heat treatments showed better tensile strength totally, i.e. the minimum level of ultimate and yield strength passed 1280 MPa and 1245MPa. The highest ultimate tensile strength could reach 1445 MPa. After (α+β) solution and aging treatment, the microstructure consists of primary α phase and transformed β phase with fine secondary α phase precipitating to improve the tensile strength effectively.

Mechanical Properties Of Cu-Based Composites with in Situ Formed Ultrafine Filaments

1981 ◽  
Vol 12 ◽  
Author(s):  
J. Bevk ◽  
W. A. Sunder ◽  
G. Dublon ◽  
David E. Cohen
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Young’S Modulus ◽  
Size Dependence ◽  
Young's Modulus ◽  
Plastic Properties ◽  
Young’S Moduli ◽  
Lattice Softening

ABSTRACTElastic and plastic properties of in situ Cu-based composites with Nb, V, and Fe filaments are reviewed. The evidence is presented for a pronounced size dependence of both the ultimate tensile strength and the Young's moduli. In composites with the smallest filaments (d∼50–200Å) and filament densities as high as 1010/cm2 dislocation density reaches values of 1013 cm/cm3. The yield stress of these samples increases dramatically over the predictions based on the “rule of mixtures” and their ultimate tensile strength approaches the estimated theoretical strength of the material (∼2.7GPa). The observed decrease of Young's modulus as a function of inverse wire diameter in the as-drawn composites is attributed to lattice softening due to high density of extended lattice defects. Upon annealing, Young's modulus increases by as much as 100% and exceeds the maximum values calculated from bulk elastic constants. Possible mechanisms leading to modulus enhancement and to related changes in magnetic and superconducting behavior of in situ composites are discussed.

scholarly journals In situ synchrotron X-ray diffraction line-profile analysis of additively manufactured Ti−6Al−4V alloy under tensile deformation

2020 ◽  
Vol 321 ◽  
pp. 03026
Author(s):  
K. Yamanaka ◽  
A. Kuroda ◽  
M. Ito ◽  
M. Mori ◽  
T. Shobu ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Line Profile ◽  
Tensile Deformation ◽  
Profile Analysis ◽  
High Energy ◽  
Line Profile Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Β Phase

In this study, the tensile deformation behavior of an electron beam melted Ti−6Al−4V alloy was examined by in situ X-ray diffraction (XRD) line-profile analysis. The as-built Ti−6Al−4V alloy specimen showed a fine acicular microstructure that was produced through the decomposition of the α′-martensite during the post-melt exposure to high temperatures. Using high-energy synchrotron radiation, XRD line-profile analysis was successfully applied for examining the evolution of dislocation structures not only in the α-matrix but also in the nanosized, low-fraction β-phase precipitates located at the interfaces between the α-laths. The results indicated that the dislocation density was initially higher in the β-phase and an increased dislocation density with increasing applied tensile strain was quantitatively captured in each constitutive phase. It can be thus concluded that the EBM Ti−6Al−4V alloy undergoes a cooperative plastic deformation between the constituent phases in the duplex microstructure. These results also suggested that XRD line-profile analysis combined with highenergy synchrotron XRD measurements can be utilized as a powerful tool for characterizing duplex microstructures in titanium alloys.

scholarly journals Effect of thermal cycling on mechanical and microstructural properties of heat-treated Ti-6Al-4V alloy

2022 ◽  
Author(s):  
Venkata Siva Teja Putti ◽  
S Manikandan ◽  
Kiran Kumar Ayyagari
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Weight Ratio ◽  
High Strength ◽  
Stress Relief ◽  
Strength Properties ◽  
Thermal Cycles ◽  
Β Phase ◽  
Solution Treated ◽  
Heat Treated

Abstract Titanium (Ti-6Al-4V) is an α+β phase-field alloy utilized in many industries due to its high strength-to-weight ratio and near-net shaping capability. Solution treated & aging, and stress relief annealing processes were performed on the samples to increase the strength and % of elongation. The heat-treated samples then thermally cycled for 500 cycles, 1000 cycles, and 1500 cycles to evaluate the microhardness and tensile properties. The presence of martensite and α2 precipitates in the thermally cycled samples was confirmed by scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD). In this investigation, at 1000 thermal cycles, all specimens show improvement in both hardness and strength when compared within the cycles. Solution-treated and aging (STA), stress relief annealing (SRA), and without any heat-treatment (WHT) processes have their highest hardness values recorded for 1000 thermal cycles, and the values are 471 HV0.5, 381 HV0.5, and 374.6HV0.5, respectively. For the SRA process, ultimate tensile strength (UTS) of 925 MPa and yield strength (YS) of 896 MPa have resulted in 1000 cycles. Similarly, at 1000 thermal cycle WHT processed samples yielded UTS of 920 MPa and YS of 885 MPa. STA process samples that are heat-treated for 1000 thermal cycles have better strength properties than SRA and WHT and had a UTS of 1530MPa and YS of 1420MPa. From a ductility point of view, a maximum elongation of 29% for the STA process has resulted. Compared to forged titanium alloy (base metal), an increase of 31% elongation and 41% ultimate tensile strength for solution treated and aging process at 1000 cycles has resulted in this investigation.

In situ Three-dimensional Observation of Rubber Materials Under Tensile Deformation

2018 ◽  
Vol 91 (10) ◽  
pp. 370-374
Author(s):  
Takeshi HIGUCHI ◽  
Hiroshi JINNAI
Keyword(s):  
Tensile Deformation ◽  
Three Dimensional

Effects of Yttrium on Microstructure and Mechanical Properties of In Situ (Al2O3+Al3Zr)p/A356 Composites

2010 ◽  
Vol 152-153 ◽  
pp. 1083-1087
Author(s):  
Bo Wang ◽  
Yu Tao Zhao ◽  
Song Li Zhang ◽  
Gang Chen ◽  
Xiao Nong Cheng
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Test Results ◽  
Microstructure And Mechanical Properties ◽  
Yttrium Addition

In-situ (Al2O3+Al3Zr)p/A356 composites were synthesized by melt reaction technology and the effects of yttrium on microstructure and mechanical properties of the composites are investigated. The results indicate that the reinforced particulates Al2O3 and Al3Zr become smaller in size with yttrium addition, the sizes are about 0.5~2μm. The distribution becomes more homogeneous, the morphologies are spheroid-shape and ellipsoid-shape, the ambitus is blunt. The mechanical properties test results show the mechanical properties of the composites are greatly enhanced. With 0.4wt.% yttrium addition, the ultimate tensile strength and yield strength of the composites reach to 388MPa and 296MPa, which are increased 35.6% and 37.0% comparing with no yttrium addition, respectively. The effect mechanisms of yttrium are discussed.

Microstructure and Tensile Properties of a 1.25Cr-0.5Mo Main Steam Pipe After Long-Term Service

2018 ◽  
Author(s):  
Bin Yang ◽  
Wen-Chun Jiang ◽  
Wen-Qi Sun ◽  
Yan-Ling Zhao ◽  
Wei-Ya Zhang
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Tensile Properties ◽  
Yield Stress ◽  
Tensile Deformation ◽  
High Yield ◽  
Micro Hardness ◽  
Steam Pipe ◽  
Main Steam

Metallographic tests, micro-hardness tests and tensile tests were conducted for a 1.25Cr-0.5Mo main steam pipe weldment served for more than 26 years. The results were compared with those for virgin material. Microstructural evolution of 1.25Cr-0.5Mo base metal was investigated. Degradation in micro-hardness and tensile properties were also studied. In addition, the tensile properties of subzones in the ex-service weldment were characterized by using miniature specimens. The results show that obvious microstructural changes including carbide coarsening, increasing inter lamella spacing and grain boundary precipitates take place after long-term service. Degradation in micro-hardness is not obvious. However, the effects of long term service on tensile deformation behavior, ultimate tensile strength and yield stress are remarkable. Based on the yield stress of micro-specimens, the order of different subzones is: WM > HAZ > BM, which is consistent with the order of different subzones based on micro-hardness. However, the ultimate tensile strength and fracture strain of HAZ are lower than BM. Brittle failures can happen more easily for HAZ due to its high yield ratio.

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