An in-situ consolidation method was developed and optimized to successfully fabricate alumina ceramics using pre-gelling starch. Our results showed that the obtained ceramics have more homogeneous microstructure, high...An in-situ consolidation method was developed and optimized to successfully fabricate alumina ceramics using pre-gelling starch. Our results showed that the obtained ceramics have more homogeneous microstructure, higher density, higher flexural strength, and favorable biocompatibility compared to the regular one. During the process, cornstarch granules swelled and deformed but no fracture was observed. After the cornstarch granules bursted, alumina particles were suspended uniformly in the three-dimensional network structure to generate a much smoother surface. Below 0.5 wt% higher cornstarch content increased the flexural strength of prepared ceramics, while above 0.5 wt% the mechanical properties were compromised. Therefore the cornstarch content of 0.5% was the optimal concentration to achieve the highest mechanical strength of the prepared ceramics, with a measured flexural strength of 341 MPa, and a relative density of 96.01%.展开更多
A new kind of in-situ ceramic consolidation molding process was investigated on the basis of the characteristics of starch swelling in water and gelatinizing when heated. The SiC ceramic suspension containing about 50...A new kind of in-situ ceramic consolidation molding process was investigated on the basis of the characteristics of starch swelling in water and gelatinizing when heated. The SiC ceramic suspension containing about 50vol% solids loading and about 3wt% starch can be cast and molded into various complex-shape SiC ceramic parts in a water-thermostat. The dry shrinkage of the green body was less than 1.0% when the solid volume fraction of SiC suspension was up to 52.5%. The density and pore size were homogeneously distributed inside the biscuits. Soaked with melt silicon in a vacuum arc furnace, the biscuits were turn into SiC ceramic materials with homogeneous structure and high performances.展开更多
基金Funded by the National Key Research and Development Program of China(Nos.2017YFC1103800,2016YFC1101605)Wuhan Key Science and Technology Project(No.2017060201010191)
文摘An in-situ consolidation method was developed and optimized to successfully fabricate alumina ceramics using pre-gelling starch. Our results showed that the obtained ceramics have more homogeneous microstructure, higher density, higher flexural strength, and favorable biocompatibility compared to the regular one. During the process, cornstarch granules swelled and deformed but no fracture was observed. After the cornstarch granules bursted, alumina particles were suspended uniformly in the three-dimensional network structure to generate a much smoother surface. Below 0.5 wt% higher cornstarch content increased the flexural strength of prepared ceramics, while above 0.5 wt% the mechanical properties were compromised. Therefore the cornstarch content of 0.5% was the optimal concentration to achieve the highest mechanical strength of the prepared ceramics, with a measured flexural strength of 341 MPa, and a relative density of 96.01%.
文摘A new kind of in-situ ceramic consolidation molding process was investigated on the basis of the characteristics of starch swelling in water and gelatinizing when heated. The SiC ceramic suspension containing about 50vol% solids loading and about 3wt% starch can be cast and molded into various complex-shape SiC ceramic parts in a water-thermostat. The dry shrinkage of the green body was less than 1.0% when the solid volume fraction of SiC suspension was up to 52.5%. The density and pore size were homogeneously distributed inside the biscuits. Soaked with melt silicon in a vacuum arc furnace, the biscuits were turn into SiC ceramic materials with homogeneous structure and high performances.
