Processing of fluorapatite surface layer on zirconia tapes by dip coating

MARÍA P. ALBANO ; LILIANA B. GARRIDO

Curitiba

Congreso; 56 Congreso Brasileiro de Cerámica; 2012

Asociación Brasilera de Cerámica

Thin fluorapatite (FA) layers on 3 mol% yttria-partially stabilized zirconia (Y-PSZ) substrates have been fabricated by dipping porous zirconia tapes into aqueous 27.4 vol.% fluorapatite slurries. Porous Y-PSZ tapes with 31.4 vol.% porosity were developed using starch and an acrylic latex as fugitive additive and binder, respectively. For comparison, Y-PSZ tapes with 12.7 vol.% porosity were fabricated without starch. The influence of the porous structure of the tape surfaces, top and bottom,on the casting rate and consequently on the layer thickness formed on each surface was studied. Layers formed on the top surface were found to be about 55 and 32 % thicker than those formed on the bottom surface for the tapes fabricated with and without starch, respectively. This difference was attributed to a greater porosity of the top surface with respect to that of the bottom one and was more pronounced for the tapes prepared with starch.