Mechanical and lamination properties of alumina green tapes obtained by aqueous tape-casting

Mechanical characterisation and lamination were carried out on alumina green tapes prepared by aqueous tape casting using two acrylic emulsions having different glass transition temperatures (T-g) as binders. The tensile strength and strain weve strongly dependent on the binder nature and content. Namely, the mechanical properties of the green tapes reflected those of the binders at room temperature: the green tapes obtained with the higher T-g binder showed a brittle behaviour, whereas those obtained with the lower T-g binder showed an elastoplastic behaviour. The mechanical properties of the green tapes prepared by mixing the two acrylic binders lies in between, giving the possibility of tailoring the flexibility and strength in the range of the values obtained for pure binders. Lamination gave vise to an increase of both green and sintered densities, compared with monolayer specimens, whatever the composition of the binder system. Such improvements significantly depended on lamination pressure, but were insensitive to lamination temperature for the two temperatures tested higher than the T-g of the two binders. (C) 1999 Elsevier Science Ltd. All rights reserved.