Authors: |
Alexandre Guignard* / Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research (IEK), IEK-1: Materials Synthesis and Processing, Germany Georg Mauer/ Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research (IEK-1), Germany Robert Vaßen/ Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research (IEK-1), Germany Detlev Stöver/ Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research (IEK-1), Germany
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Abstract: |
The manufacture of submicrometer-structured coatings by thermal spraying is subjected nowadays to increasing research efforts in order to obtain unique and often enhanced properties compared to conventional coatings. Injecting suspensions of submicron ceramic particles into the plasma jet or the flame enables to deposit finely-structured coatings. Such fine microstructures are desired for applications in the field of thermal barrier coatings (TBCs) for gas turbines. Therefore, suspension plasma sprayed (SPS) TBCs show unique mechanical, thermal and optical properties compared to conventional atmospheric plasma sprayed (APS) TBCs. They have thus the potential of providing increased TBC performances under severe thermo-mechanical loading. Experimental results show the capability of SPS to obtain YSZ coatings with high density of vertical segmentation cracks, yielding high strain tolerance and low Young's modulus, while the porosity is still large compared to APS segmented coatings. Besides, sintering behavior of complete TBC systems under a thermal gradient exposure is of high importance. The evolution of the coating microstructure during thermal cycling test in our thermal cyclic rigs at very high temperature (1400°C) and its effect on the coating properties were investigated.
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