Supersonic Induction Plasma Spraying of Yttria Stabilised Zirconia Films

In this paper, supersonic RF induction plasma deposition of Yttria Stabilized Zirconia (YSZ) has been developed in order to produce dense solid electrolyte membranes for Solid Oxide Fuel Cells (SOFC). Different RF induction plasma torch configurations were tested. The results show that high density layers could be obtained using a supersonic Laval nozzle integrated on a standard torch. 50 to 100 um YSZ coatings with porosity of near 1% could be obtained using this technique at relatively high deposition rates (10g/min.). Attention has been given to the thin coating porosity measurement by using a proper calibration and back scattered electron micrographs of the deposit cross-section coupled with image analysis. Absolute porosity has been measured by using this technique described in another paper of the same conference.

Supersonic Induction Plasma Spraying of Dense YSZ Electrolyte Membranes

In this paper, RF induction plasma deposition of Yttria Stabilized Zirconia (YSZ) is studied with the objective of producing dense solid electrolyte membranes for Solid Oxide Fuel Cells (SOFC). Different RF induction plasma torch configurations were tested. The results show that high density layers could be obtained using a supersonic Laval nozzle attachment on a standard torch. Coating with apparent porosity of less than 1% could be obtained using this technique at relatively high deposition rates. Optical or electron microscopic examination of the deposit coupled with image analysis show, however, that porosity measurements using these techniques can suffer from relatively large discrepancies depending on equipment setting. A discussion is presented of the validity of this porosity measurement technique.

Analysis of Induction Plasma Deposition Dynamics for Control

Plasma torches are used in a variety of different applications including forming corrosion and wear resistant coatings, near net shape manufacture, and production of metal matrix composites. The dynamics of a low order nonlinear dynamic model of the process are analyzed to obtain insight into developing an appropriate control structure.