Inkjet printing of yttria stabilized zirconia nano particles on metal substrates

This paper describes a novel methodology of coating Yttria stabilized Zirconia (YSZ) suspensions on AISI316L steel substrates and involves a micro structural investigation to understand the sintering behavior. Nano sized particles are used at lowering of sintering temperature. Nano particle suspension inks prepared through high energy milling process is visibly stable due to ionic charge carriers in binder and solvent. Deposition of suspended material was done through inkjet printing (IJP) and spin coating (SC) processes. Print head offset in X and Y directions lead to fabrication of homogeneous layers. Inkjet printing at elevated temperatures is useful especially in controlling nano particle seepage through porous substrates. Low temperature sintering of suspended particles in the ink leads to development of porous YSZ films due to the presence of carrier solvent and binder/dispersants in the ink. Sintered films exhibit completely stable tetragonal zirconia with uniformly porous microstructure. Pore sizes of 50 nm and 100 nm have been reported at least for inkjet printed and spin coated films respectively. The homogeneity observed in pores of YSZ film is a typical characteristic of inkjet printing process which is attributed to the layer by layer stacking of nano particles during the deposition process.