| Résumé | MCrAlX powder compositions (M=Ni,Co and X= Y, Hf, Si or combination) are often thermally sprayed (TS) via vacuum plasma spray (VPS), low pressure plasma spray (LPPS) or high velocity oxy-fuel (HVOF) to produce high temperature oxidation and hot corrosion resistant bond coats (BC) for thermal barrier coatings (TBCs). Cold spray (CS) technology is currently considered as a promising alternative to the traditional TS solutions having the advantage of delivering oxide-free and very dense metallic coatings at relatively lower costs.
Here, we first present high-pressure CS deposition of CoNiCrAlY, NiCoCrAlY and NiCoCrAlYHfSi and discuss the influence of feedstock properties on the deposited BCs. CFD numerical simulation is employed to tailor the spray conditions based on the feedstock characteristics. Secondly, we present the laser assisted cold spray (LACS) deposition of NiCoCrAlYHfSi BCs using a low-pressure CS system. We show that LACS can be successfully used to deposit this particular powder while eliminating nozzle erosion and low deposition efficiency disadvantages observed during conventional CS.
Lastly, high temperature isothermal and cyclic oxidation of TBC architectures having cold sprayed BCs are presented. Their performance is discussed in conjunction with the TGO formation and growth as well as the effect of the BCs surface roughness on adhesion to the air plasma spray (APS) deposited YSZ ceramic top coats. |
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