PROCESSING AND MORPHOLOGICAL ANALYSIS OF A TWO-LAYER CERAMIC STRUCTURE FOR CAPILLARY EVAPORATORS
Isadora Schramm Deschamps1; Marcos Vinício Oro1; Matheus de Lorenzo Oliveira1; Lucas Freitas Berti2; Marcio Celso Fredel1; Edson Bazzo1
1 Federal University of Santa Catarina; 2 Federal Technological University of Paraná
doi:10.20906/CPS/COB-2015-1816
Resumo
The present work concerns the manufacturing, characterization of ceramic wicks used in two phase heat transfer devices, as capillary pumped loops (CPLs) and loop heat pipes (LHPs). Such devices are designed for thermal control in microgravity applications and use a wick for pumping the working fluid by capillarity. Double layer alumina wicks presenting each a different porosity were manufactured in order to improve their thermal behavior and permeability. The porous structures were obtained by a slip casting method, associated with polyurethane (PU) foams acting as porogenic agent. The foams were immersed in the mold during casting and thereafter removed by pyrolysis during the sintering process. Characterization prior to processing includes rheology optimization of the slurry, through viscosity analysis, sintering steps determination by dilatometry, and SEM microscopy analysis of the strut size and morphology of the PU foams. Ceramic wick's characterization included porosity, critical diameter and capillary pressure. Each layer presented, respectively average porosity of 39.95% and 45.61% , average critical diameters of 14.9 μm and 91.2 μm and average capillary pressure of 19.7 kPa and 3.2 kPa.
Palavras-chave: ceramic wick; slip casting; freeze casting; CPL; capillary pump