Cold Spray MCrAlY Coatings on Single-Crystal Superalloy Using Nitrogen: Properties and Economics

2020 ◽  
Vol 29 (7) ◽  
pp. 1628-1642 ◽  
Author(s):  
Deliang Leon Guo ◽  
Daniel MacDonald ◽  
Linruo Zhao ◽  
Bertrand Jodoin
Keyword(s):  
Single Crystal ◽  
Cold Spray ◽  
Single Crystal Superalloy ◽  
Mcraly Coatings

Cold Spray MCrAlY Coatings on Single-Crystal Ni-Base Superalloys: A Substrate Perspective

2021 ◽  
Author(s):  
Deliang Guo ◽  
Bertrand Jodoin ◽  
Linruo Zhao
Keyword(s):  
Heat Treatment ◽  
Single Crystal ◽  
Cold Spray ◽  
Gas Turbines ◽  
Solution Heat Treatment ◽  
Spray Deposition ◽  
Isothermal Oxidation ◽  
Heat Treatments ◽  
Mcraly Coatings ◽  
Oxidation Performance

Abstract The hot-section components of modern gas turbines (e.g.; turbine blades and vanes) are typically manufactured from Nibase superalloys. To develop the γ/γ' microstructure that imparts superior thermomechanical and creep properties; Nibase superalloys usually require three distinct heat treatments: first a solution heat treatment; followed by primary aging; and finally secondary aging. To achieve oxidation resistance; MCrAlY coatings are applied on the superalloy components as either environmental coatings or bond coats for thermal barrier coatings. In this study; the effects of different processing sequences on MCrAlY coating characteristics and short-term isothermal oxidation performance were investigated. Specifically; cold spray deposition of NiCoCrAlTaY coatings was carried out on single-crystal Ni-base superalloy substrates that underwent various degrees of the full heat treatments prior to being coated. The remaining required heat treatments for the superalloy substrates were then performed on the coated samples after the cold spray deposition. The microstructures of the CMSX-4 substrates and NiCoCrAlTaY coatings were characterized after each heat treatment. Isothermal oxidation performance of the coated samples prepared using different sequences was evaluated at 1100°C for 2 hours. The results suggested a promising procedure of performing only solution heat treatment on the superalloy substrate before coating deposition and then primary aging and secondary aging on the coated samples. This processing sequence could potentially improve the oxidation performance of MCrAlY coatings; as the aging processes can be used to effectively homogenize coating microstructure and promote a thin thermally grown oxide (TGO) scale prior to actual isothermal oxidation.

Crystal Plasticity Assessment to Crystallographic Stage I Cracking in a Ni-Based Single Crystal Superalloy

2018 ◽  
Author(s):  
Motoki Sakaguchi ◽  
Ryota Komamura ◽  
Mana Higaki ◽  
Xiaosheng Chen ◽  
Hirotsugu Inoue
Keyword(s):  
Single Crystal ◽  
Crystal Plasticity ◽  
Stage I ◽  
Single Crystal Superalloy

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.

The Effect of Tensile Stress on Oxidation Behavior of Nickel-Base Single Crystal Superalloy

2021 ◽  
pp. 109737
Author(s):  
Hai-Qing Pei ◽  
Meng Li ◽  
Ping Wang ◽  
Xiao-Hu Yao ◽  
Zhi-Xun Wen ◽  
...  
Keyword(s):  
Tensile Stress ◽  
Single Crystal ◽  
Oxidation Behavior ◽  
Single Crystal Superalloy ◽  
Nickel Base

scholarly journals Creep Damage Repair of a Nickel-Based Single Crystal Superalloy Based on Heat Treatment

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 623
Author(s):  
Xiaoyan Wang ◽  
Meng Li ◽  
Yuansheng Wang ◽  
Chengjiang Zhang ◽  
Zhixun Wen
Keyword(s):  
Heat Treatment ◽  
Single Crystal ◽  
Creep Damage ◽  
Primary Creep ◽  
Single Crystal Superalloy ◽  
Secondary Creep ◽  
Creep Life ◽  
Phase Coarsening ◽  
Damage Repair ◽  
Creep Time

Taking nickel-based single crystal superalloy DD6 as the research object, different degrees of creep damage were prefabricated by creep interruption tests, and then the creep damage was repaired by the restoration heat treatment system of solid solution heat treatment and two-stage aging heat treatment. The results show that with the creep time increasing, the alloy underwent microstructure evolution including γ′ phase coarsening, N-type rafting and de-rafting. After the restoration heat treatment, the coarse rafted γ′ phase of creep damaged specimens dissolved, precipitated, grew up, and became cubic again. Except for the specimens with creep interruption of 100 h, the γ′ phase can basically achieve the same arrangement as the γ′ phase of the original sample. The comparison of the secondary creep test shows that the steady-state creep stage of the test piece after the restoration heat treatment is relatively increased, and the total creep life can reach the same level as the primary creep life. The high temperature creep properties of the tested alloy are basically recovered, and the restoration heat treatment effect is good.

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