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

Mechanical characterisation and lamination were carried out on alumina gree n tapes prepared by aqueous tape casting using two acrylic emulsions having different glass transition temperatures (T-g) as binders. The tensile stre ngth and strain weve strongly dependent on the binder nature and content. N amely, the mechanical properties of the green tapes reflected those of the binders at room temperature: the green tapes obtained with the higher T-g b inder 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, gi ving the possibility of tailoring the flexibility and strength in the range of the values obtained for pure binders. Lamination gave vise to an increa se of both green and sintered densities, compared with monolayer specimens, whatever the composition of the binder system. Such improvements significa ntly depended on lamination pressure, but were insensitive to lamination te mperature for the two temperatures tested higher than the T-g of the two bi nders. (C) 1999 Elsevier Science Ltd. All rights reserved.