Effects of yttrium on microstructure and mechanical properties of a directionally solidified single crystal superalloy

2019 ◽  
Vol 752 ◽  
pp. 86-92 ◽  
Author(s):  
Kai Guan ◽  
Zhaohui Huang ◽  
Renjie Cui ◽  
Jianchao Qin
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Single Crystal Superalloy ◽  
Directionally Solidified ◽  
Microstructure And Mechanical Properties

scholarly journals Microstructure and mechanical properties of a new nickel-based single crystal superalloy

2020 ◽  
Vol 9 (5) ◽  
pp. 11641-11649 ◽  
Author(s):  
Zhao Shang ◽  
Xianping Wei ◽  
Dazhuo Song ◽  
Juntao Zou ◽  
Shuhua Liang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Single Crystal Superalloy ◽  
Microstructure And Mechanical Properties

scholarly journals Microstructure and Mechanical Properties of Diffusion-Bonded CoCrNi-Based Medium-Entropy Alloy to DD5 Single-Crystal Superalloy Joint

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1127
Author(s):  
Shiwei Li ◽  
Xianjun Sun ◽  
Yajie Du ◽  
Yu Peng ◽  
Yipeng Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Single Crystal ◽  
Diffusion Zone ◽  
Diffusion Bonding ◽  
Bonding Temperature ◽  
Single Crystal Superalloy ◽  
Interface Bonding ◽  
Microstructure And Mechanical Properties ◽  
Joint Diffusion

This study focuses on the diffusion bonding of a CoCrNi-based medium-entropy alloy (MEA) to a DD5 single-crystal superalloy. The microstructure and mechanical properties of the joint diffusion-bonded at variable bonding temperatures were investigated. The formation of diffusion zone, mainly composed of the Ni3(Al, Ti)-type γ′ precipitates and Ni-rich MEA matrix, effectively guaranteed the reliable joining of MEA and DD5 substrates. As the bonding temperature increased, so did the width of the diffusion zone, and the interfacial microvoids significantly closed, representing the enhancement of interface bonding. Both tensile strength and elongation of the joint diffusion-bonded at 1110 °C were superior to those of the joints diffusion-bonded at low temperatures (1020, 1050, and 1080 °C), and the maximum tensile strength and elongation of 1045 MPa and 22.7% were obtained. However, elevated temperature produced an adverse effect that appeared as grain coarsening of the MEA substrate. The ductile fracture of the joint occurred in the MEA substrate (1110 °C), whereas the tensile strength was lower than that of the MEA before diffusion bonding (approximately 1.3 GPa).

Effect of Hf Content on Oxidation Resistance of Single Crystal Superalloy at 1000°C

2014 ◽  
Vol 915-916 ◽  
pp. 562-566 ◽  
Author(s):  
Z.X. Shi ◽  
Shi Zhong Liu ◽  
M. Han ◽  
J.R. Li
Keyword(s):  
Grain Size ◽  
Single Crystal ◽  
Oxide Scale ◽  
Oxide Layer ◽  
Oxidation Resistance ◽  
Isothermal Oxidation ◽  
Single Crystal Superalloy ◽  
Ambient Atmosphere ◽  
Directionally Solidified ◽  
Better Than

The specimens of single crystal superalloy DD6 with 0.10% Hf and 0.47% Hf were prepared in the directionally solidified furnace. The effect of Hf content on the isothermal oxidation resistance of the second generation single crystal superalloy DD6 was studied at 1000°Cin ambient atmosphere. Morphology of oxides was examined by SEM, and their composition was analyzed by XRD and EDS. The experimental results show that the oxidation resistance of DD6 alloy with 0.47% Hf is better than that of the alloy with 0.10% Hf. The alloy with different Hf content all obeys parabolic rate law during oxidation for 100h at 1000°C. The increase of Hf content can promote the Al2O3 formation and decreases the proportion of NiO. The oxide grain size and the thickness of the oxide layer all reduce with increasing of Hf content. The oxide scale of the alloy with different Hf content is made up of an outer NiO layer with a small amount of Co3O4, inner Al2O3 and Cr2O3 layer with a small amount of TaO2.

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