Quantifying the convective drying behaviour of cemented carbide paste extrudates
Autor: | H. Ferstl, S.L. Rough, D.I. Wilson |
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Přispěvatelé: | Wilson, Ian [0000-0003-3950-9165], Apollo - University of Cambridge Repository |
Rok vydání: | 2019 |
Předmět: |
Convection
End effect Wax Materials science General Chemical Engineering Evaporation 4004 Chemical Engineering 02 engineering and technology 021001 nanoscience & nanotechnology Aspect ratio (image) Rod 020401 chemical engineering visual_art visual_art.visual_art_medium Cemented carbide 0204 chemical engineering Composite material 0210 nano-technology 40 Engineering |
DOI: | 10.17863/cam.38827 |
Popis: | The drying behaviour of cemented carbide paste extrudates was investigated in an industrial drying oven at temperatures in the range 40 to 100C. In addition to the expected evaporation of the volatile alcohol component of the paste binder, extra mass loss was recorded at the higher temperatures. This was attributed to the removal of wax present in the paste particulates. The rate of drying was investigated by removing parts periodically, weighing them and returning them to the oven. Discs, cylindrical rods and tubes with different aspect ratios were tested in order to identify a general drying model. End effects were confirmed to be important for short parts, such as rods with aspect ratio < 10. Whilst a shrinking core model could be fitted to the disc drying data very well, it failed to describe the results for rods. A pseudo-Fickian model was found to describe all three geometries reasonably well. The effective diffusion coefficients obtained by fitting the model to the data were similar in magnitude but exhibited systematic variation with rod diameter, which were attributed to differences in strain-induced microstructure during extrusion. |
Databáze: | OpenAIRE |
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