Effects of Nb on the High Temperature Mechanical Properties of TiNiAl Alloys

2007 ◽  
Vol 546-549 ◽  
pp. 1477-1480 ◽  
Author(s):  
Gao Song Qiu ◽  
Xin Qing Zhao ◽  
Ling Jie Meng ◽  
Hui Bin Xu
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Yield Strength ◽  
Yield Stress ◽  
Microstructure Evolution ◽  
High Yield ◽  
Strengthening Effect ◽  
High Temperature Mechanical Properties ◽  
Solution Strengthening ◽  
Nb Addition

A series of NiTiAl based alloys with different amount of Nb addition were prepared and the effects of Nb on both the mechanical properties and microstructure evolution were investigated. The addition of Nb can remarkably enhance the high temperature yield strength of these alloys. The highest yield strength of the alloys with 10 at% Nb reaches 1237MPa at 873K and 875MPa at 973K, respectively. The Ti2Ni(Al,Nb) precipitates and the solution strengthening effect might be responsible for the high yield stress achieved at high temperature.

Effects of W Addition on Microstructure and 650 °C Mechanical Properties of Ti-Al-Sn-Zr-Mo-Nb-W-Si Alloy

2021 ◽  
Vol 904 ◽  
pp. 53-58
Author(s):  
Wen Jing Zhang ◽  
Hao Feng Xie ◽  
Li Jun Peng ◽  
Zhen Yang ◽  
Guo Jie Huang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
High Temperature ◽  
Yield Strength ◽  
Stress Rupture ◽  
Tensile Tests ◽  
Optical Microscope ◽  
High Yield ◽  
Strengthening Effect ◽  
Α Phase

The influence of W addition on microstructure and mechanical properties of Ti-Al-Sn-Zr-Mo-Nb-W-Si high temperature titanium alloys are investigated by optical microscope (OM), scanning electron microscopy (SEM), electron probe microanalysis (EPMA), tensile tests and large stress endurance tests at 650 °C. The results show that W is mainly solubilized in β phase. Microstructure observations indicate an obvious reduction in the size of transformed β structure (βt), primary α phase (αp) and the thickness of secondary lamellar α phase (αL), with the increase of W content. It is also observed that adding more W could improve the elongation, tensile strength and large stress rupture properties at 650 °C. However, combined with previous research, adding more β stabilizing elements could refine the size of each phase, which will be detrimental to the high temperature yield strength of the alloy. Therefore, in order to reasonably utilize the strengthening effect of W and make the alloy have high yield strength and tensile strength at 650 °C, its content should be controlled between 1 ~ 2 wt%

High Temperature Mechanical Behavior of Some Advanced Ni3Al

1986 ◽  
Vol 81 ◽  
Author(s):  
S. E. Hsu ◽  
N. N. Hsu ◽  
C. H. Tong ◽  
C. Y. Ma ◽  
S. Y. Lee
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Yield Strength ◽  
Mechanical Behavior ◽  
Single Phase ◽  
Rupture Strength ◽  
Strengthening Mechanisms ◽  
High Temperature Mechanical Properties ◽  
Higher Temperature

AbstractHigh temperature mechanical properties of various Zr and Cr strengthened single phase Ni3Al are investigated, with emphasis on the ability of each element to elevate Tp, the temperature corresponding to the peak yield strength. It is observed that Zr is a very effective strengthener, more so below Tp than above it, while a combination of Cr and Zr is capable of shifting Tp to a higher temperature. The combination results in an effective improvement of the rupture strength of Ni3Al. The strengthening mechanisms of each element will be discussed in this paper.

Mechanical Properties of Ga1–xInxAs

1985 ◽  
Vol 53 ◽  
Author(s):  
S. Guruswamy ◽  
J.P. Hirth ◽  
K.T. Faber
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
High Temperature ◽  
Strengthening Effect ◽  
Plateau Stress ◽  
Solid Solution Strengthening ◽  
Stress Region ◽  
Solution Strengthening ◽  
Concentration Levels ◽  
Undoped Gaas

ABSTRACTSubstantial solid solution strengthening of GaAs by In acting as InAs4 units has recently been predicted. This strengthening could account for the reduction of dislocation density in GaAs single crystals grown from the melt. High temperature hardness measurements up to 700ºC have been carried out on (100) GaAs and Ga0.9975 In0.0025 As wafers. Results show a significant strengthening effect in In—doped GaAs even at concentration levels of about 0.2 wt%. A temperature independent flow stress region is observed for both these alloys. The In—doped GaAs shows ahigher plateau stress level compared to the undoped GaAs. The results are consistent with the solid solution strengthening model.

scholarly journals Study on the Relationship between High Temperature Mechanical Properties and Precipitates Evolution of 7085 Al Alloy after Long Time Thermal Exposures

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1483
Author(s):  
Jinxin Zang ◽  
Pan Dai ◽  
Yanqing Yang ◽  
Shuai Liu ◽  
Bin Huang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
High Temperature ◽  
Tensile Properties ◽  
Volume Fraction ◽  
Al Alloy ◽  
Strengthening Effect ◽  
Nano Scale ◽  
High Temperature Mechanical Properties ◽  
The Relationship

The requirement for 7085 Al alloy as large airframe parts has been increasing due to its low quenching sensitivity and high strength. However, the relationship between high temperature mechanical properties and the evolution of precipitates in hot environments is still unclear. In this work, thermal exposure followed by tensile tests were conducted on the 7085 Al alloy at various temperatures (100 °C, 125 °C, 150 °C and 175 °C). Variations of hardness, electrical conductivity and tensile properties were investigated. The evolution of the nano scale precipitates was also quantitatively characterized by transmission electron microscopy (TEM). The results show that the hardness and electrical conductivity of the alloy are more sensitive to the temperature than to the time. The strength decreases continuously with the increase of temperature due to the transformation from η′ to η phase during the process. Furthermore, the main η phase in the alloy transformed from V3 and V4 to V1 and V2 variants when the temperature was 125 °C. Additionally, with increasing the temperature, the average precipitate radius increased, meanwhile the volume fraction and number density of the precipitates decreased. The strengthening effect of nano scale precipitates on tensile properties of the alloy was calculated and analyzed.

scholarly journals The Effect of the Cooling Rates on the Microstructure and High-Temperature Mechanical Properties of a Nickel-Based Single Crystal Superalloy

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4256
Author(s):  
Xiao-Yan Wang ◽  
Meng Li ◽  
Zhi-Xun Wen
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Single Crystal ◽  
Solution Treatment ◽  
Single Crystal Superalloy ◽  
Air Cooling ◽  
Strengthening Effect ◽  
Cooling Rates ◽  
High Temperature Mechanical Properties ◽  
High Temperature Tensile

The as-cast alloy of nickel-based single-crystal superalloy was used as the research object. After four hours of solution treatment at 1315 °C, four cooling rates (water cooling (WC), air cooling (AC) and furnace cooling (FC1/FC2)) were used to reduce the alloy to room temperature. Four different microstructures of nickel-based superalloy material were prepared. A high-temperature tensile test at 980 °C was carried out to study the influence of various rates on the formation of the material’s microstructure and to further obtain the influence of different microstructures on the high-temperature mechanical properties of the materials. The results show that an increase of cooling rate resulted in a larger γ′ phase nucleation rate, formation of a smaller γ′ phase and a greater number. When air cooling was used, the uniformity of the γ′ phase and the coherence relationship between the γ′ phase and the γ phase were the best. At the same time, the test alloy had the best high-temperature tensile properties, and the material showed a certain degree of plasticity. TEM test results showed that the test alloy mainly blocked dislocations from traveling in the material through the strengthening effect of γ′, and that AC had the strongest hindering effect on γ′ dislocation movement.

Influences of Al, Ce on the Microstructure and Mechanical Properties of As-Cast Mg-6Zn Alloy

2013 ◽  
Vol 747-748 ◽  
pp. 470-477
Author(s):  
Rui Dong Liu ◽  
Xu Guang Dong ◽  
Fu Jun Wei ◽  
Yuan Sheng Yang
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Yield Strength ◽  
Ultimate Strength ◽  
Magnesium Alloys ◽  
Room Temperature ◽  
Volume Fraction ◽  
High Temperature Mechanical Properties ◽  
Microstructure And Mechanical Properties ◽  
Al Addition

The effects of minor Al and Ce on the microstructures, room-temperature and high-temperature mechanical properties of as-cast Mg-6Zn magnesium alloys were investigated. With the Al addition into Mg-6Zn alloy, the coarse eutectic Mg51Zn20phases were refined and distributed discontinuously. After adding 0.5wt.% Ce into Mg-6Zn-1Al alloy, a new needle-like Al2CeZn2phase was observed. Meanwhile, the volume fraction of Mg51Zn20phase decreased and the semi-continuous Mg51Zn20phase became discontinuous globular morphology. It has been observed that the addition of Ce element coarsens the grains, and 1wt.% Al addition enhanced the yield strength and ultimate strength from 86.35MPa, 229MPa to 90.7MPa, 238MPa, respectively. Moreover, the Ce addition can significantly increase the high-temperature mechanical properties of cast Mg-6Zn-1Al alloy.

scholarly journals Microstructure Evolution and Mechanical Properties of Novel γ/γ′ Two-Phase Strengthened Ir-Based Superalloys

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1171
Author(s):  
Xiao Fang ◽  
Rui Hu ◽  
Jieren Yang ◽  
Yi Liu ◽  
Ming Wen
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Microstructure Evolution ◽  
Quaternary Alloys ◽  
Two Phase ◽  
Solid Solution Strengthening ◽  
New Class ◽  
High Temperature Mechanical Properties ◽  
Evolution Phase ◽  
Ultrahigh Temperature

Ir-based superalloys are irreplaceable in some specific harsh conditions regardless of their cost and high density. In order to develop a new class of Ir-based superalloy for future ultrahigh-temperature applications, the microstructure evolution, phase relationships, and mechanical properties of Ir–Al–W–Ta alloys with γ/γ′ two-phase structure were investigated. Room- and high-temperature compressions at 1300 °C, and room-temperature nanoindentation for the Ta-containing Ir–6Al–13W alloys were conducted. The results show that the addition of Ta can significantly improve the high-temperature mechanical properties, but does not change the fracture mode of the Ir-based two-phase superalloys. The compressive strength of quaternary alloys can be attributed to the precipitation of γ′-Ir3(Al, W) phase and solid solution strengthening. The microstructure and mechanical properties of Ir–Al–W–Ta quaternary alloys exhibit promising characteristics for the development of high-temperature materials.

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