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 the γ′ Phase on the Mechanical Properties of a Nickel-Based Single Crystal Superalloy

2021 ◽  
Vol 1023 ◽  
pp. 45-52
Author(s):  
Xiao Yan Wang ◽  
Meng Li ◽  
Zhi Xun Wen
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Single Crystal ◽  
Tensile Properties ◽  
Room Temperature ◽  
Solution Treatment ◽  
Single Crystal Superalloy ◽  
Original Material ◽  
Solid Solution Treatment ◽  
The Matrix

After solid solution treatment at 1335°C for 4 hours and cooling to room temperature at different rate, the nickel-based single crystal superalloy were made into three kinds of nickel-based single crystal superalloy materials containing different size γ′ phases, respectively. The tensile test of I-shaped specimens was carried out at 980°C, and their effect of γ′ phase microstructure on the tensile properties was studied. The results show that the yielding strength of the material air-cooled to room temperature was lower than that with cooling rate at 0.15°C/s, but both of them were lower than the yielding strength of original material. Little difference was found on the elastic modulus of I-shaped specimens made of three kinds of materials. When the cubic degree of the γ′ phase is higher and the size is larger, the tensile properties of the material is better, which can be attributed to the larger size and narrower channel of the matrix phase that lead to higher dislocation resistance.

The Effect of Microalloying B on the High Temperature Mechanical Properties of Ti3Al

1988 ◽  
Vol 133 ◽  
Author(s):  
Joseph W. Newkirk ◽  
Gerald B. Feldewerth
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Tensile Properties ◽  
Grain Refinement ◽  
High Temperature Mechanical Properties ◽  
High Temperature Tensile ◽  
High Temperature Tensile Properties

ABSTRACTThe effect of adding boron to Ti3Al on the microstructure and high temperature tensile properties has been studied. Boron caused a large grain refinement that dominated the tensile properties at all temperatures. Particles of Ti2B were found in all of the boron containing alloys. TiB was found only at concentrations of 0.1% B or more.

High-Temperature Mechanical Properties of As-Extruded ZK60

2005 ◽  
Vol 488-489 ◽  
pp. 753-758
Author(s):  
Wei Wu ◽  
C.M. Hong ◽  
Li Jia Chen ◽  
Yue Wang ◽  
Lin Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Strain Rate ◽  
Initial Strain Rate ◽  
Offset Yield Strength ◽  
High Temperature Mechanical Properties ◽  
Fracture Behaviors ◽  
Elongation To Failure ◽  
Zk60 Alloy ◽  
High Temperature Tensile

High-temperature tensile and fracture behaviors of as-extruded ZK60 alloy were investigated. It was evident from the experiments that with decreasing temperature and increasing strain rate, the 0.2% offset yield strength and ultimate tensile strength of the alloy increased while the elongation to failure decreased. The flowing stress of as-extruded ZK60 alloy during plastic deformation was proportioned to the reciprocal of temperature. At the initial strain rate of 5×10-4s-1, the calculated active energy at 300°C was about 93.4 kJ/mol.

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 Application research progress of hot isostatic pressing technology in nickel-based single crystal superalloy

2020 ◽  
Vol 155 ◽  
pp. 01012
Author(s):  
Jun Wang ◽  
Zhaojun Jiang
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Single Crystal ◽  
Hot Isostatic Pressing ◽  
Single Crystal Superalloy ◽  
Research Progress ◽  
Application Research ◽  
Isostatic Pressing ◽  
Increasing Demand ◽  
Pressing Technology

Since the introduction of hot isostatic pressing (HIP) technology, it has been widely used in powder metallurgy forming and improving the densification of castings. With the increasing demand for the performance of nickel-based single crystal superalloy, more and more scholars started research on the application of hot isostatic pressing in nickel-based single crystal superalloy. This article summarizes the current research progress in the application of hot isostatic pressing to the high temperature of nickel-based single crystals, explains the elimination effect of hot isostatic pressing on porosity and other pore defects in nickel-based single crystal superalloy, analyzes the pore healing mechanism, and the changes in mechanical properties such as tensile, endurance, and fatigue of the alloy after applying hot isostatic pressing are shown. Finally, the future development of China’s hot isostatic pressing technology is prospected.

scholarly journals Study on High-Temperature Mechanical Properties of Fe–Mn–C–Al TWIP/TRIP Steel

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 821
Author(s):  
Guangkai Yang ◽  
Changling Zhuang ◽  
Changrong Li ◽  
Fangjie Lan ◽  
Hanjie Yao
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Low Temperature ◽  
Tensile Fracture ◽  
Temperature Range ◽  
High Temperature Mechanical Properties ◽  
Ductility Trough ◽  
Different Temperatures ◽  
Reduction Of Area ◽  
High Temperature Tensile

In this study, high-temperature tensile tests were carried out on a Gleeble-3500 thermal simulator under a strain rate of ε = 1 × 10−3 s−1 in the temperature range of 600–1310 °C. The hot deformation process of Fe–15.3Mn–0.58C–2.3Al TWIP/TRIP at different temperatures was studied. In the whole tested temperature range, the reduction of area ranged from 47.3 to 89.4% and reached the maximum value of 89.4% at 1275 °C. Assuming that 60% reduction of area is relative ductility trough, the high-temperature ductility trough was from 1275 °C to the melting point temperature, the medium-temperature ductility trough was 1000–1250 °C, and the low-temperature ductility trough was around 600 °C. The phase transformation process of the steel was analyzed by Thermo-Calc thermodynamics software. It was found that ferrite transformation occurred at 646 °C, and the austenite was softened by a small amount of ferrite, resulting in the reduction of thermoplastic and formation of the low-temperature ductility trough. However, the small difference in thermoplasticity in the low-temperature ductility trough was attributed to the small amount of ferrite and the low transformation temperature of ferrite. The tensile fracture at different temperatures was characterized by means of optical microscopy and scanning electron microscopy. It was found that there were Al2O3, AlN, MnO, and MnS(Se) impurities in the fracture. The abnormal points of thermoplasticity showed that the inclusions had a significant effect on the high-temperature mechanical properties. The results of EBSD local orientation difference analysis showed that the temperature range with good plasticity was around 1275 °C. Under large deformation extent, the phase difference in the internal position of the grain was larger than that in the grain boundary. The defect density in the grain was large, and the high dislocation density was the main deformation mechanism in the high-temperature tensile process.

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