|
2611 |
|
Thursday, September 29, 2011, Saal B2.1 2:50 PM Plasma Spraying 2 |
|
Deposition of La-Sr-Fe-Co perovskite coatings with different microstructures by low pressure plasma spraying |
|
Nikolay Zotov* / IEK-1
Forschungszentrum Jülich, Germany Andreas Hospach/ IEK-1, Forschungszentrum Jülich, Germany Georg Mauer/ IEK-1, Forschungszentrum Jülich, Germany Doris Sebold/ IEK-1, Forschungszentrum Jülich, Germany Robert Vaßen/ IEK-1, Forschungszentrum Jülich, Germany |
|
Mixed ion-electron conducting oxides such as La1-xSrxFe1-yCoyO3 (LSFC) have potential applications as gas sensors, oxygen-permeable membranes, solid oxygen fuel cell electrodes and oxidation catalysts. Most of these applications require thin dense materials with well-defined microstructures. The low pressure plasma spraying physical vapour deposition (LPPS-PVD) technology, operating at pressures below 50 mbar, has the potential for producing very thin and dense ceramic or metallic coatings as well as coverage of large areas in short times compared to standard thermal spray processes. These properties make LPPS-PVD a suitable candidate for preparation of LSFC-based oxygen separation membranes. In the present contribution we report first results in producing LSFC coatings with different microstructures by LPPS-PVD using DC plasma with different Ar-He compositions, different powder injection parameters and substrate temperatures. The plasma spraying was performed with a commercial spraying system and O3CP gun operating at input power of about 120 kW. Deposition with Ar-rich plasma at lower powder feed rates leads to the formation of homogeneous dense coatings with layered microstructure and small amounts of closed inter-layer porosity. Coatings deposited with He-rich plasma at higher powder feed rates exhibit moreporous columnar structures. Different growth mechanisms of the LSFC coatings depending on the oxygen partial pressure in the vacuum chamber are discussed. |