scholarly journals Study on abnormal hot corrosion behavior of nickel-based single-crystal superalloy at 900 °C after drilling

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Zehao Chen ◽  
Mengmeng Wu ◽  
Yanling Pei ◽  
Shusuo Li ◽  
Shengkai Gong
Keyword(s):  
Diffusion Process ◽  
Single Crystal ◽  
Oxide Layer ◽  
Corrosion Behavior ◽  
Surface Stress ◽  
Hot Corrosion ◽  
Single Crystal Superalloy ◽  
Alloying Elements ◽  
Stable Oxide ◽  
Change Of Microstructure

AbstractThe hot corrosion behavior of nickel-based single-crystal superalloy after drilling is investigated at 900 °C. The characteristics of hot corrosion after drilling which are different from normal hot corrosion are reflected in the formation of a more stable oxide layer and less severe spallation. The change of microstructure around the hole is the main reason for the formation of a stable oxide layer during hot corrosion by changing the diffusion process of alloying elements. Subsequently, the formation of a stable oxide layer can reduce the effect of spalling by optimizing surface stress.

Hot corrosion behavior of Pt-Ir modified aluminide coatings on the nickel-base single crystal superalloy TMS-82+

2007 ◽  
Vol 22 (1) ◽  
pp. 206-216 ◽  
Author(s):  
Y.N. Wu ◽  
A. Yamaguchi ◽  
H. Murakami ◽  
S. Kuroda
Keyword(s):  
Single Crystal ◽  
Corrosion Behavior ◽  
Hot Corrosion ◽  
Aluminide Coating ◽  
Mass Gain ◽  
Heating Time ◽  
Single Crystal Superalloy ◽  
Aluminide Coatings ◽  
Corrosion Kinetics ◽  
Nickel Base

Platinum-iridium films (Ir = 0, 32, 46, 83, 100 at.%) were deposited on the nickel-base single crystal superalloy through magnetron sputtering. After annealing and aluminizing, the Pt-Ir modified aluminide coatings mainly consisted of PtAl2 and β-(Ni,Pt,Ir)Al phases. Hot corrosion resistance of Pt-Ir modified aluminide coatings with the different Ir contents were evaluated by exposure at 1173 K in the presence of the 90%Na2SO4 + 10%NaCl (wt%) salt deposits. The corrosion kinetics curves of the specimens were plotted up to 100 h heating time. The phase constitution, morphology of corrosion products, and element concentrations along the cross section were also measured. The lowest mass gain (0.299 mg/cm2, after 100 h) was observed for Pt-46Ir aluminide coating because the dense and continuous protective Al2O3 scale formed. Phase transformation from β-(Ni,Pt)Al to γ′-(Ni,Pt)3Al, characteristics of the scale, and protection by Pt/Ir enriched layer had the important effects on the hot corrosion behavior of modified aluminide coatings.

Effect of Pt-rich position on the hot corrosion behavior of NiCoCrAlY coating for a single-crystal superalloy

2020 ◽  
Vol 395 ◽  
pp. 125938 ◽  
Author(s):  
Y.F. Yang ◽  
P. Ren ◽  
Z.B. Bao ◽  
S.L. Zhu ◽  
F.H. Wang ◽  
...  
Keyword(s):  
Single Crystal ◽  
Corrosion Behavior ◽  
Hot Corrosion ◽  
Single Crystal Superalloy

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.

Solid Reactions between Enamel and O-Phase Ti-Al-Nb Intermetallics at 800 °C

2008 ◽  
Vol 595-598 ◽  
pp. 233-238 ◽  
Author(s):  
D.Y. Zheng ◽  
Yu Ming Xiong ◽  
Sheng Long Zhu ◽  
Fu Hui Wang ◽  
Wei Tao Wu
Keyword(s):  
Oxide Layer ◽  
Corrosion Behavior ◽  
Growth Rates ◽  
Hot Corrosion ◽  
Enamel Coating ◽  
Tem Analysis ◽  
Silica Films ◽  
Α Al2o3 ◽  
O Phase ◽  
Xrd And Tem

The specimens of O-phase Ti-22Al-25Nb (at%) intermetallics coated with silica-based enamel received mass gains of about 1 mg/cm2, after 300 h of oxidation or hot corrosion at 800 °C. These rates were much faster than the growth rates of silica films at the same temperature. To understand this phenomena, the specimens were analyzed using SEM, XRD, EPMA and TEM. An oxide layer with thickness of several μm was observed at the enamel/substrate interface of the coated specimens after either oxidation or hot corrosion. XRD and TEM analysis revealed the newly formed oxide layer was composed of α-Al2O3, Al2SiO5, Al2TiO5, rutile-TiO2 and NbO2. It was shown by EPMA profiling that an Al-depleted zone was located just beneath the oxides. It was proposed that the solid reactions between the enamel coating and the O-phase Ti-Al-Nb played important roles for the oxidation and hot corrosion behavior of the coated specimens.

scholarly journals Directional Migration Behavior of Alloying Elements in the Rafting Process of the Single Crystal Superalloy DD6

2016 ◽  
Vol 45 (5) ◽  
pp. 1147-1151 ◽  
Author(s):  
Zhang Shiming ◽  
Yu Jingui ◽  
Huang Zeyin ◽  
Huang Rong ◽  
Liu Shengfa ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystal Superalloy ◽  
Alloying Elements ◽  
Migration Behavior ◽  
Directional Migration
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