Microstructural and high-temperature cyclic oxidation response of NiCoCrAlY coatings with and without SiC + ZrB2 reactive-element dispenser

2021 ◽  
pp. 109617
Author(s):  
Gabriel Israel Vásquez Hernández ◽  
Marco Aurelio González Albarrán ◽  
Eduardo Rodríguez de Anda ◽  
Juan Carlos Díaz Guillen ◽  
Omar Jiménez Alemán ◽  
...  
Keyword(s):  
High Temperature ◽  
Cyclic Oxidation ◽  
Reactive Element

Cyclic-Oxidation of RexOy-Modified Aluminide Coating

2012 ◽  
Vol 557-559 ◽  
pp. 1721-1726
Author(s):  
Yong Dong Wang ◽  
Yue Bo Zhou
Keyword(s):  
Composite Film ◽  
Cyclic Oxidation ◽  
Aluminide Coating ◽  
Pack Cementation ◽  
Reactive Element ◽  
Aluminide Coatings ◽  
Oxidation In Air

Reactive reactive element oxide RexOy (Re=Ce, Y)-modified aluminide coatings were developed by aluminizing the as-codeposited Ni-RexOy composite film using pack cementation method at 1100°C for 4 h. By comparison, aluminizing was also performed with the same condition on an as-deposited Ni film without RexOy particles. SEM/EDAX and TEM results indicated that the co-deposited CeO2 or Y2O3 particls were homogeneously dispersed in the finer-grain nanocrystalline Ni grains. The cyclic oxidation in air at 900°C indicated that the RexOy -modified aluminide coatings were profoundly spallation resistance as compared to the RexOy -free coatings due to the formation of a continuous adherent α-Al2O3 scale.

Effect of Hf Addition on High Temperature Properties of Ir-Containing Alloy Coatings

2007 ◽  
Vol 546-549 ◽  
pp. 1689-1694 ◽  
Author(s):  
Hideyuki Murakami ◽  
K. Kamiya ◽  
Akihiro Yamaguchi ◽  
Ying Na Wu ◽  
Seiji Kuroda
Keyword(s):  
High Temperature ◽  
Cyclic Oxidation ◽  
Flat Surface ◽  
Small Difference ◽  
Aluminide Coating ◽  
High Temperature Properties ◽  
Aluminide Coatings ◽  
Cyclic Oxidation Test ◽  
Hf Addition ◽  
Pack Cementation Process

In the present study, high temperature properties of Ir-modified and Ir-Hf-modified aluminide coatings on Ni-based single crystal superalloy TMS-82+ were discussed. They were prepared by depositing pure Ir and Ir-Hf alloys on TMS-82+ using magnetron sputtering and EB-PVD, followed by a conventional Al-pack cementation process. The effects of Hf addition on the oxidation resistance and top-coat spallation resistance were investigated. Cyclic oxidation test at 1423K for 1h as one heating cycle revealed that while there is a small difference in oxidation kinetics and spallation lives between Ir and Ir-Hf coatings, drastic difference in surface morphology was observed. After 50 oxidation cycles the Ir-modified aluminide coating showed surface rumpling whereas the Ir-Hf modified aluminide coatings kept the flat surface. It was also revealed that excessive addition of Hf promoted the internal oxidation, resulting in the deterioration of substrates. These results agree with the conventional Pt-modified aluminide coatings and Ni-Al-Hf alloys.

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