scholarly journals Improving the Oxidation Resistance in Advanced Single Crystal Nickel-Based Superalloys for Turbine Applications

10.2172/9241 ◽  
1999 ◽  
Author(s):  
K.B. Alexander ◽  
E.A. Kenik ◽  
M.K. Miller ◽  
L.S. Lin ◽  
A.D. Cetel
Keyword(s):  
Single Crystal ◽  
Oxidation Resistance

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.

Oxidation Resistance Improvement of Ni-Base Single-Crystal Superalloy Melted in a CaO Crucible

2019 ◽  
Vol 50 (8) ◽  
pp. 3903-3911 ◽  
Author(s):  
Takuya Sugiyama ◽  
Satoshi Utada ◽  
Tadaharu Yokokawa ◽  
Makoto Osawa ◽  
Kyoko Kawagishi ◽  
...  
Keyword(s):  
Single Crystal ◽  
Oxidation Resistance ◽  
Single Crystal Superalloy ◽  
Resistance Improvement

The role of Re in improving the oxidation-resistance of a Re modified PtAl coating on Mo-rich single crystal superalloy

2020 ◽  
Vol 58 ◽  
pp. 63-72 ◽  
Author(s):  
Jingchen Li ◽  
Liangliang Wei ◽  
Jian He ◽  
Hao Chen ◽  
Hongbo Guo
Keyword(s):  
Single Crystal ◽  
Oxidation Resistance ◽  
Single Crystal Superalloy

OXIDATION RESISTANCE AND MICROSTRUCTURE OF Pt AND PtIr DIFFUSION COATINGS ON Ni BASED SINGLE CRYSTAL SUPERALLOYS BY ELECTROPLATING METHOD

2019 ◽  
Vol 57 (6) ◽  
pp. 714
Author(s):  
Tue Chi Dao ◽  
Hideyuki Murakami ◽  
Le Thi Hong Lien
Keyword(s):  
Single Crystal ◽  
Oxidation Resistance ◽  
Cyclic Oxidation ◽  
Treatment Process ◽  
Heat Treatment Process ◽  
Oxidation Test ◽  
Diffusion Coatings ◽  
Cyclic Oxidation Test ◽  
Annealing Heat Treatment ◽  
Kirkendall Voids

In this study, Pt and PtIr diffusion coatings on Ni based single crystal superalloys were fabricated by an electroplating method followed by an annealing heat treatment process. The microstructure and phase constitution of the coatings were studied by SEM/EDS and XRD methods. The cyclic oxidation test at 1150oC was conducted to investigate the oxidation resistance of the coatings. The results showed that the addition of Ir in the coating led to the formation of α(NiPt2Al) phase and reduced the formation Kirkendall voids in the coating after 100 cycle oxidation test.

Oxidation Behavior of Ru-Containing Ni-Base Single-Crystal Superalloys

2006 ◽  
Vol 522-523 ◽  
pp. 317-322 ◽  
Author(s):  
Kyoko Kawagishi ◽  
Atsushi Sato ◽  
Akihiro Sato ◽  
Toshiharu Kobayashi ◽  
Hiroshi Harada
Keyword(s):  
High Temperature ◽  
Single Crystal ◽  
Oxidation Resistance ◽  
Platinum Group Metals ◽  
Rhenium Oxide ◽  
Scale Spallation ◽  
Spinel Layer ◽  
Temperature Oxidation ◽  
Tcp Phase ◽  
Advanced Generation

The 4th and advanced generation Ni-base single crystal superalloys, which contain large amounts of refractory metals for strengthening and platinum group metals, e.g., Ru, for TCP-phase prevention, show excellent high-temperature strengths. However, these alloying elements seem to decrease high-temperature oxidation resistance. In this study, Ni-base superalloys with various amounts of Ta, Re and Ru were examined in isothermal and cyclic exposures at 1373K to investigate the effect on the oxide growth rate and resistance to scale spallation. Structures of the oxide for the alloys were analyzed by XRD, SEM and EDX, and the oxidation kinetics is discussed. Ru and Re were found to degrade the oxidation resistance by the vaporization of their oxide. Ta-rich oxide in the spinel layer affects to stabilize ruthenium and rhenium oxide in the scale and improve the oxidation resistance of Ru-containing Ni-base superalloys.

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