Isothermal Oxidation of Pt Modified and Ru Modified Aluminide Coating on a Fourth Generation Single Crystal Superalloy

2006 ◽  
Vol 522-523 ◽  
pp. 301-308
Author(s):  
Yuki Matsuoka ◽  
Yasuo Matsunaga ◽  
Kiyokazu Nakagawa ◽  
Shigeji Taniguchi
Keyword(s):  
Single Crystal ◽  
Aluminide Coating ◽  
Isothermal Oxidation ◽  
Single Crystal Superalloy ◽  
Fourth Generation ◽  
Outward Diffusion ◽  
Secondary Reaction Zone ◽  
Refractory Elements ◽  
Topologically Close Packed ◽  
Pt Modification

Isothermal oxidation behavior of a 4th generation Ni-base single crystal superalloy with Pt-modified and Ru-modified aluminide coating was examined in a temperature range 1223 to 1373 K in air. Both Pt and Ru modification improve the oxidation resistance of a simple aluminide coating, especially above 1273 K. They allow thin protective and continuous Al2O3 scales to be intact for at least 500 h at temperatures up to 1323 K. However, the Pt modification drastically accelerates the formation of a secondary reaction zone (SRZ). This suggests that Pt promotes the formation of a topologically close-packed phase by lowering the solubility of refractory elements in γ-Ni. In contrast, the Ru modification reduces the SRZ, and is expected to enhance the phase stability under the coating by preventing the depletion of Ru due to its outward diffusion.

scholarly journals The Interdiffusion Behavior of NiCoCrAlYHf Coating Deposited by Arc Ion Plating on Carburized Ni-Based Single Crystal Superalloy

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7401
Author(s):  
Zun Chen ◽  
Jinyan Zhong ◽  
Shanglin Yang ◽  
Songmei Li ◽  
Jianhua Liu ◽  
...  
Keyword(s):  
Single Crystal ◽  
Cyclic Oxidation ◽  
Oxidation Time ◽  
Single Crystal Superalloy ◽  
Outward Diffusion ◽  
Arc Ion Plating ◽  
Ion Plating ◽  
Refractory Elements ◽  
Carburized Layer ◽  
Interdiffusion Coefficients

In the present study, arc ion plating (AIP) was used to prepare a NiCoCrAlYHf coating (HY5 coating) on a carburized third-generation single-crystal superalloy DD10. The interdiffusion behavior of the carburized superalloy with an HY5 coating was investigated for a 1000 h oxidation time at 1100 °C. Carburization enhanced the interfacial bonding force and improved the microstructure of the NiCoCrAlYHf coating. An interdiffusion zone (IDZ) formed after a 300 h oxidation time, and the formation of a carburized layer effectively suppressed an inward diffusion of cobalt, aluminium, and chromium to the DD10 superalloy as well as an outward diffusion of nickel and refractory elements for instance rhenium and tungsten to the HY5 coating that occurred in static air at 1100 °C. The roles of the carburized layer in affecting thermal cyclic oxidation and element interdiffusion were studied. Subsequently, a modified form of the Boltzmann–Matano analysis was used to present the interdiffusion coefficients of aluminium.

New Phases in a Multicomponent High Ruthenium Single Crystal Superalloy

2005 ◽  
Vol 475-479 ◽  
pp. 655-660 ◽  
Author(s):  
Q. Feng ◽  
L.J. Rowland ◽  
T.M. Pollock
Keyword(s):  
Single Crystal ◽  
Dendritic Structure ◽  
Thermal Exposure ◽  
Single Crystal Superalloy ◽  
Heusler Phase ◽  
Topologically Close Packed ◽  
Tcp Phases ◽  
Δ Phase

Three unusual Ru-rich phases have been identified in a multicomponent Ni-base single crystal superalloy, including a L21 Ru2AlTa Heusler phase, a B2 RuAl phase and a hcp Re(Ru)-rich δ phase. These phases have their own preferential precipitation location within the dendritic structure. No conventional topologically-close-packed (TCP) phases have been observed with thermal exposure at 950oC for 1500 hours.

Oxidation behaviour of NiCoCrAlYHfZr coating on a fourth generation single crystal superalloy

2021 ◽  
pp. 109522
Author(s):  
S.B. Liu ◽  
W. Li ◽  
L.B. Fu ◽  
T.G. Wang ◽  
S.M. Jiang ◽  
...  
Keyword(s):  
Single Crystal ◽  
Oxidation Behaviour ◽  
Single Crystal Superalloy ◽  
Fourth Generation

Isothermal Oxidation Behavior of Ru Modified Aluminide Coating on a Fourth Generation Single Crystal Superalloy

2006 ◽  
Vol 512 ◽  
pp. 111-116 ◽  
Author(s):  
Yuki Matsuoka ◽  
Kazuyoshi Chikugo ◽  
Takakazu Suzuki ◽  
Yasuo Matsunaga ◽  
Shigeji Taniguchi
Keyword(s):  
Phase Transformation ◽  
Oxidation Behavior ◽  
Coating Layer ◽  
Aluminide Coating ◽  
Isothermal Oxidation ◽  
Fourth Generation ◽  
Short Term ◽  
Cross Sectional ◽  
Local Oxidation ◽  
Sectional Analysis

Ru coating prior to aluminizing is one of the effective methods to reduce the harmful intermediate layer that forms under the coating (SRZ) on a 4th generation Ni-base SC superalloy. This study examined the short-term isothermal oxidation behavior of this Ru-modified coating at 1373 K in air. Surface observation by SEM showed that the scale becomes flat and uniform in comparison to simple aluminide coating. XRD and cross-sectional analysis results also showed that phase transformation from β-NiAl to γ’-Ni3Al seldom occurs in the Ru-modified coating layer leading to the prevention of local oxidation.

Isothermal Oxidation of René N5 at 1150°C

2018 ◽  
Author(s):  
Megan Walker ◽  
Xiao Huang
Keyword(s):  
Single Crystal ◽  
Exposure Time ◽  
Bond Coat ◽  
Isothermal Oxidation ◽  
Oxidation Behaviour ◽  
Single Crystal Superalloy ◽  
Short Term ◽  
Alumina Layer ◽  
Spinel Layer ◽  
Oxide Spallation

In this study, single crystal superalloy René N5 was exposed in air at 1150 °C for up to 16 hours to evaluate the alloy’s short-term oxidation behaviour and the potential for developing a no-bond coat TBC system. The results showed that after 1 hour of exposure, a three layered oxide developed on the surface, consisting of spinel, Ta-containing oxide and alumina just above the substrate. After 4 hours of exposure, oxide spallation occurred; this became more pronounced after 16 hours. The oxide spallation took place between the top spinel layer and alumina layer, where Ta-rich oxide was more abundant. All samples tested for 0.5, 1, 2, 4 and 16 hours developed alumina near the substrate while the occurrence of NiO, spinel and Ta-oxides varied, depending upon the exposure time.

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.

Sign in / Sign up

Export Citation Format

Share Document