scholarly journals Topologically Close Packed Phases in an Experimental Rhenium-Containing Single Crystal Superalloy

2000 ◽  
Author(s):  
C.M.F. Rae ◽  
M.S.A. Karunaratne ◽  
C.J. Small ◽  
R.W. Broomfield ◽  
C.N. Jones ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystal Superalloy ◽  
Topologically Close Packed

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.

Fracture Mode of a Ni-Based Single Crystal Superalloy Containing Topologically Close-Packed Phases at Ambient Temperature

2014 ◽  
Vol 45 (4) ◽  
pp. 1665-1669 ◽  
Author(s):  
Qianying Shi ◽  
Xianfei Ding ◽  
Jingyang Chen ◽  
Xiaona Zhang ◽  
Yunrong Zheng ◽  
...  
Keyword(s):  
Ambient Temperature ◽  
Single Crystal ◽  
Fracture Mode ◽  
Single Crystal Superalloy ◽  
Topologically Close Packed

scholarly journals Microstructure investigations of Pt-modified γ′-Ni3Al + γ-Ni coatings on Ni-based superalloys

2010 ◽  
Vol 25 (6) ◽  
pp. 1191-1195 ◽  
Author(s):  
Guanghui Cao ◽  
Taoping Ou ◽  
Hua Jiang ◽  
Alan M. Russell
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Single Crystal ◽  
Energy Dispersive ◽  
Single Crystal Superalloy ◽  
Refractory Element ◽  
Cross Sectional ◽  
X Ray ◽  
Topologically Close Packed ◽  
Transmission Electron

The microstructure of Pt-modified γ′-Ni3Al + γ-Ni coating on CMSX-4 single-crystal superalloy has been investigated by transmission electron microscopy (TEM). Cross-sectional TEM analyses showed the presence of precipitates in the coating. This precipitate was identified as the hexagonal topologically close-packed (TCP) μ phase with lattice parameters a = 0.473 nm and c = 2.565 nm. The energy-dispersive x-ray (EDX) spectrum of the μ phase suggested a refractory element rich compound comprising the elements Re, W, and Co. Twin domains parallel to (001) were found in the μ phase. The mechanisms of the μ phase and twinning formation were discussed.

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.

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