Comparison between filter pressing and isostatic pressing for submicrometer alumina powder has been systematically made. Obvious improvements in true porosity, sintering behaviour, and microstructure of green compacts...Comparison between filter pressing and isostatic pressing for submicrometer alumina powder has been systematically made. Obvious improvements in true porosity, sintering behaviour, and microstructure of green compacts without cracking and in agglomeration of final ceramics have been achieved.展开更多
The influence of pH on the rheological properties of concentrated alumina suspensions was investigated. At various pH values, the alumina exhibited pseudoplastic, near Bingham flow behaviors. The fully-deflocculated s...The influence of pH on the rheological properties of concentrated alumina suspensions was investigated. At various pH values, the alumina exhibited pseudoplastic, near Bingham flow behaviors. The fully-deflocculated suspensions exhibited Newtonian flow behaviors, while the fully-flocculated suspensions demonstrated very high viscosity and shear yield stress.展开更多
The pH dependence of the extrapolated shear yield stress for Alcoa A16 a-Al2O3 suspensions at the powder volume fraction of 0.27 with and without addition of both polyvinyl alcohol (PVA) and polyethylene glycol (PEG) ...The pH dependence of the extrapolated shear yield stress for Alcoa A16 a-Al2O3 suspensions at the powder volume fraction of 0.27 with and without addition of both polyvinyl alcohol (PVA) and polyethylene glycol (PEG) each at fixed 0.18% of the powder mass was studied. With the polymer added, the full deflocculation of the suspension shifts from about pH=4 to around pH=1.5, at which the minimum value of shear yield stress is higher than that at pH=4. The addition of both PVA and PEG was found to prevent the filter cake from cracking.展开更多
文摘Comparison between filter pressing and isostatic pressing for submicrometer alumina powder has been systematically made. Obvious improvements in true porosity, sintering behaviour, and microstructure of green compacts without cracking and in agglomeration of final ceramics have been achieved.
基金Partly supported by Scientific Research Foundation for Returned Overseas Scholars from State Education Committee of China
文摘The influence of pH on the rheological properties of concentrated alumina suspensions was investigated. At various pH values, the alumina exhibited pseudoplastic, near Bingham flow behaviors. The fully-deflocculated suspensions exhibited Newtonian flow behaviors, while the fully-flocculated suspensions demonstrated very high viscosity and shear yield stress.
文摘The pH dependence of the extrapolated shear yield stress for Alcoa A16 a-Al2O3 suspensions at the powder volume fraction of 0.27 with and without addition of both polyvinyl alcohol (PVA) and polyethylene glycol (PEG) each at fixed 0.18% of the powder mass was studied. With the polymer added, the full deflocculation of the suspension shifts from about pH=4 to around pH=1.5, at which the minimum value of shear yield stress is higher than that at pH=4. The addition of both PVA and PEG was found to prevent the filter cake from cracking.
