A MODEL FOR THE DIFFUSION OF ORGANIC ADDITIVES DURING THERMOLYSIS OF A CERAMIC BODY.
PHILOS MAG A
267 - 280.
The removal or organic additives which are used to assemble ceramic particles into pre-determined shapes, by diffusion during thermolysis, is modelled taking into account the simultaneous creation of surface porosity and distributed porosity in the ceramic body. A flat-plate geometry is considered and the model is used to predict the relationship between the critical heating rate Z(c), which is the fastest heating rate that allows thermolysis to proceed without creating defects in the ceramic, the plate thickness 2r(0), a factor X which determines the volume fraction of distributed porosity in the ceramic and the volume fraction (V-c) of ceramic in the plate. The effect of shrinkage on Z(c) due to the movement of ceramic particles during thermolysis is also considered. It is shown that Z(c) is dominated by r(0). In comparison, the effect of V-c and X on Z(c) is negligible. The increase in V-c due to shrinkage had very little effect on Z(c). A major achievement of the present work is the development of maps which relate Z(c), V-c, r(0) and type of porosity formed.
|Title:||A MODEL FOR THE DIFFUSION OF ORGANIC ADDITIVES DURING THERMOLYSIS OF A CERAMIC BODY|
|Keywords:||INJECTION-MOLDED CERAMICS, BINDER REMOVAL, VEHICLE, BODIES, FABRICATION, POROSITY, BURNOUT|
|UCL classification:||UCL > School of BEAMS
UCL > School of BEAMS > Faculty of Engineering Science
Archive Staff Only