Comparative tensile behavior of freestanding γ-γ′ and β-(Ni,Pt)Al bond coats and effect on tensile properties of coated superalloy

Simulation Study on Microstructure Development in a MCrAlY Superalloy System

“…MCrAlY's DBTT was quite dependent on its composition but was much lower than diffusion-type coatings [28]. For Ni20Cr9-11AlY, the DBTT was about 200 ºC [25], so the MCrAlY coating used in this study (Ni22Cr10AlY) should have a super ductility at the high temperatures investigated. Furthermore, this Ni22Cr10AlY coating had a γ/γ' microstructure below 900 ºC after a long oxidation which may provide a good strength for the coating as well.…”

“…As the cuboidal γ/γ' structure usually had an excellent ductility and high strength, this MCrAlY coating may perform a good comprehensive mechanical property with a good compatibility with the superalloy substrate at the intermediate temperatures (700~900 ℃). It has been demonstrated that the γ/γ' diffusion-type coating can decrease the ductility of superalloy by introducing cracks due to their brittle behavior [25][26][27][28]. MZ Alam's results showed the free-standing γ/γ' diffusion-type coating was brittle at 870ºC [25].…”

“…It has been demonstrated that the γ/γ' diffusion-type coating can decrease the ductility of superalloy by introducing cracks due to their brittle behavior [25][26][27][28]. MZ Alam's results showed the free-standing γ/γ' diffusion-type coating was brittle at 870ºC [25]. The DBTT (ductile-to-brittle transformation temperature) of the diffusion coatings was usually above 900 ºC.…”

Effect of Pt on Stress Rupture Properties of Pt-Modified Nickel Aluminide Coatings at 1100 °C

“…Currently, researchers have also conducted some studies on the failure behavior of PtAl coatings under complex muti-field coupling environments [8][9][10][11][12][13][14][15][16][17]. Most of them concentrated on the impact of different loading conditions, such as tension [8][9][10][11], creep [9][10][11][12][13][14][15], fatigue [16][17][18], and thermo-mechanical fatigue [19], on the mechanical properties of PtAl coatings from room temperature to the service temperature. In general, except for high-cycle fatigue at a high temperature, depositing the PtAl coating would decrease the mechanical strength of the substrate superalloy but improve its ductility at elevated temperatures.…”

A Trial to Design γ/γ′ Bond Coat in Ni–Al–Cr Mode TBCs Aided by Phase-Field Simulation

“…Recently, a new generation of γ + γ two-phase bond coat [4][5][6][7] has attracted much attention due to the fact that it has better chemical compatibility with the Ni-based superalloy matrix and displays insignificant rumpling during the thermal circulation [4] compared with the previous two commonly used types of bond coats, i.e., Pt-modified nickel aluminide [8,9] (β-phase) and Ni-Co-Cr-Al-Y system (i.e., β-NiAl phase + γ-Ni solid solution [10][11][12], or β-NiAl phase + γ -Ni 3 Al [13][14][15][16]), and thus it is widely used in aerospace industry. A series of recent investigations [5,6] also indicate that Pt-modified…”