Evolution of a diffusion aluminide bond coat for thermal barrier coatings during thermal cycling

Anisotropic TGO rumpling in EB-PVD thermal barrier coatings under in-phase thermomechanical loading

“…5). The TGO layer in the y-z section shows clear rumpling similar to what has been observed in isothermal fatigue tests [18][19]. (Although most observations of TGO rumpling have been on PtNiAl bond coats, rumpling has also been observed in some instances on MCrAlY bond coats, e.g.…”

“…Although rumpling of the TGO layer has been a crucial research subject because of its inherent link to TBC reliability and lifetime [12][13][14][15][16][17][18][19], the undulation behavior is usually studied under cyclic conditions without externally applied loads, or by creep tests under isothermal conditions [18][19]. Reports on the combined effect of thermal cycling and applied loading (hereafter denoted as thermo-mechanical fatigue, or TMF) are scarce.…”

The displacement of the thermally grown oxide in thermal barrier systems upon temperature cycling

“…Results for a Pt -aluminide system are summarized on Fig. 10 [38]. They can be idealized as high temperature strength, bc (s Y ) min above T 2 , between 5 and 50 MPa, with a rapid rise at lower temperatures.…”

“…10. Yield strength of a Pt -aluminide bond coat as a function of temperature [38]. The inset shows the stress/strain response at high temperature as a function of strain rate.…”

Evolution of surface morphology of thermo-mechanically cycled NiCoCrAlY bond coats

“…6. The (yield or creep) strength at the highest temperatures, (σ bc Y ) HT , is in general difficult to measure and can be hard to dif ferentiate from each other [24,25]. Thus, we will study the effect of the high temperature strength on the morphological instability by varying the value of the high temperature (time independent) yield strength in the calculations.…”