| dc.description.abstract | This study aims to investigate the effects of different processes, different particle sizes, different temperature of sintering processes and adding different potential reinforcement materials in the ceramic core.
When ceramic powder was added with 1wt% sodium carbonate and 1wt% potassium chloride, the sintered ceramic sample obtained high flexural strength of 7.74MPa. Effects of particle sizes (base on the Andreasen Eq.), sintering processing parameters on the flexural strength of sintered samples were studied. Experimental results found that using the fine particle (size #100) and sintering temperature at for 4 hours could yield high flexural strength.
The aluminum oxide fiber, aluminum oxide powder, nickel powder, and copper wire were further added in the ceramic powder to see the reinforcement effect. Experimental results indicated that the flexural strength of adding varying reinforced material could produce 15.2MPan in adding copper wire, 17.6MPa in adding nickel powders, and 18.7MPa in adding aluminum powder. A highest flexural strength of 21.1 MPa was measured when 0.5wt% aluminum oxide fiber was added in the ceramic sample. Increasing aluminum oxide fiber content increase the porosity of sintered ceramic to also decrease the bulk density and flexural strength.
Last but not least, ceramic cores were prepared for hot pouring test in the lost-wax casting process. The result showed that the ceramic specimens that sintered at for 2 hours got better collapsibility than those sintered at for 4 hours. | en_US |