Colloidal processing and characterization of TiO2–MnO‐doped alumina/alumina slurries and tapes

Abstract

AbstractAqueous slurries of alumina doped with manganese and titanium oxides were developed. The powders and tapes were investigated by scanning electron (SEM) microscopy, X‐ray diffractometry (XRD), and thermal analyses (TG/DSC). The stability and rheology of colloidal suspensions of undoped and doped alumina suspensions were investigated. At neutral pH of 7, pure alumina and MnO–TiO2 dopant particles present positive and negative surface charges and are prone to heterocoagulation. Optimized colloidal processing through proper adjustment of parameters was achieved to reach particle stabilization. The surface charge of the oxide particles was negative, and the suspensions did not agglomerate at a pH of 7 and higher. Tapes were cast, dried, and burned out. The thermal analyses revealed the release of residual water and decomposition of short‐chain organics at temperatures under 215°C and of long‐chain additives over 300°C.