Optimization of Ta Content of a Third Generation Ni3Al Base Single Crystal Superalloy

2015 ◽  
Vol 816 ◽  
pp. 304-309
Author(s):  
Song Ming Han ◽  
Wei Li ◽  
Yue Ma ◽  
Xin Bao Zhao ◽  
Shu Suo Li ◽  
...  
Keyword(s):  
Single Crystal ◽  
Thermodynamic Calculation ◽  
Volume Fraction ◽  
Primary Dendrite ◽  
Solution Treatment ◽  
Experimental Results ◽  
Single Crystal Superalloy ◽  
Third Generation ◽  
Primary Dendrite Arm Spacing ◽  
Calculation Results

In order to optimize the Ta content of a newly developed 3rd generation Ni3Al-based single crystal superalloy, a series of alloys with the varying of Ta content of 3.0, 4.2, 4.5, 6.0wt. % were prepared. The experimental results showed that with the addition of Ta, the size and volume fraction of bulky γ' phase significantly increased while the primary dendrite arm spacing decreased. Meanwhile, the difficulty of solution treatment significantly increased with increasing Ta content. And the thermodynamic calculation results showed that the volume fractions of γ' phase in this series of alloys were significantly higher than those of typical Ni based single crystal superalloys, indicating that the 3rd generation Ni3Al based single crystal superalloys can serve in the temperature of 1150oC to 1200oC.

Directional Solidification Behavior of CMSX-6 Superalloy

2014 ◽  
Vol 788 ◽  
pp. 554-559
Author(s):  
Shuai Zheng ◽  
Yu Liang Jia ◽  
Jiao Tang
Keyword(s):  
Single Crystal ◽  
Directional Solidification ◽  
Thermal Gradient ◽  
First Generation ◽  
Primary Dendrite ◽  
Solidification Rate ◽  
Experimental Results ◽  
Single Crystal Superalloy ◽  
Solidification Behavior ◽  
Rate Range

The directional solidification behavior of a first generation single crystal superalloy CMSX-6 was investigated. The solidification rate range in 25μm/s to 100μm/s and a thermal gradient G of 30K/cm were used for the present study. The experimental results show that the primary dendrite arm space (PDAS) decreased from (432±8) μm to (369±4) μm as the solidification rate increased, and the sizes of the eutectic pools also decreased as the solidification rate increased. And the volume fractions of eutectic γ/γ' were about 7% to 9% with different solidification rate. The γ/γ'- eutectic was comprised with coarse γ' phase and fine γ/γ' network. The morphology of the γ/γ’ eutectic supported the possibility that the solidification of γ/γ’ eutectic initiates with the formation of fine γ/γ’.

Effect of Solid Solution Heat Treatment on Microstructures of the Third Generation Single Crystal Superalloy DD9

2013 ◽  
Vol 747-748 ◽  
pp. 549-558 ◽  
Author(s):  
Xiao Guang Wang ◽  
Jia Rong Li ◽  
Zhen Xue Shi ◽  
Shi Zhong Liu
Keyword(s):  
Solid Solution ◽  
Single Crystal ◽  
Solution Treatment ◽  
Optical Microscope ◽  
Single Crystal Superalloy ◽  
Solution Temperature ◽  
Third Generation ◽  
The Third ◽  
Solid Solution Treatment ◽  
Solution Treated

An observation was conducted on the microstructures of as-cast as well as solid solution treated the third generation single crystal superalloy DD9 using optical microscope and SEM. The effects of solid solution temperature and time on the eutectic fractions of γ/γ and size of γ of the alloy were investigated. The results showed that the microstructure of DD9 was uniform. W and Re segregated to the dendrite cores while Al, Ta and Nb were enriched in interdendritic regions during solidification. The eutectic fractions of γ/γ reduced with the solid solution temperature raising and the solid solution time prolonging. When solid solution temperature increased to 1340, the eutectic in the alloy was entirely dissolved. The size of γ in dendritic cores was consistent, however the size of γ in interdendritic regions was gradually decreased with the increase of solid solution treatment and time, eventually the sizes of γ were completely uniform at the temperature of 1340

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.

scholarly journals Formation and evolution of porosity during high temperature creep of a nickel-based single crystal superalloy

2020 ◽  
Vol 155 ◽  
pp. 01005
Author(s):  
Weiwei Liu ◽  
Yuanyuan Guo ◽  
Mai Zhang ◽  
Jian Zhang
Keyword(s):  
Electron Microscope ◽  
High Temperature ◽  
Single Crystal ◽  
Volume Fraction ◽  
Great Influence ◽  
Single Crystal Superalloy ◽  
Creep Process ◽  
Steady Creep ◽  
Transmission Electron ◽  
Formation And Evolution

A Re-containing single-crystal superalloy was used to research the high temperature low stress creep behavior. Transmission electron microscope, scanning electron microscope and some other research methods are employed. The results and analysis are summarized below: Two mechanisms for the steady creep are found in this experiment. The volume fraction of pores after creep test at 1100°C increased more than 2 times compared with that before test, but the increasing at 1000°C is relatively small, which reveals that temperature has an great influence on the formation of pore during creep; There are two types of pores associated with fracture during the creep process. One is the casting shrinkage located between the interdentritic, which is formed in the solidification of the alloy. Another type of pore is nucleated and growing during the creep deformation.

Transverse Tensile Properties of a Nickel-based Third Generation Single Crystal Superalloy

2018 ◽  
Vol 47 (10) ◽  
pp. 2964-2969
Author(s):  
Yang Wanpeng ◽  
Li Jiarong ◽  
Liu Shizhong ◽  
Shi Zhenxue ◽  
Zhao Jinqian ◽  
...  
Keyword(s):  
Single Crystal ◽  
Tensile Properties ◽  
Single Crystal Superalloy ◽  
Third Generation ◽  
Transverse Tensile

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.

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