Zirconia Based Sensor Tubes Fabricated by Plasma Technology

Plasma spraying, originally a surfacing technology used for ceramic coating of metal and non-metal substrates, is also suitable for the production of bulk ceramics, such as pipes, crucibles and sensors, etc. from various materials or their combinations. In this work, magnesium oxide stabilized zirconia based sensor tubes, with 100 to 200 μm thick layers, were produced by plasma spraying and they were further densified by sintering. The structure and the microstructure were investigated by scanning electron microscopy (SEM), and X-ray diffraction (XRD) techniques. It was found that as-sprayed sensor tubes have a lamellar structure. After sintering, the lamellar microstructure changed into granular-type structure.