چكيده به لاتين
According to considering the great importance of 3D printing of ceramic materials, this study investigated the relationship between the effects of composition and particle size on the flowability and printability of clay-silicon carbide paste using an extrusion-based 3D printer. This ceramic composite can be used as ceramic foam filter, energy storage system, and water filtration in the ceramic industry. Also, the effect of polymer additives on the flow behavior of SiC-clay composite was studied. In the fefferkorn test, it was observed that with the increasing amount of silicon carbide in the SiC-clay paste, workability decreased from 39.09 to 24.71%. the rheometric results showed that the addition of Polyethylene glycol polymer from 2.5 to 10% by weight, in high content, improves the flow behavior of the mix and reduces the amount of water required by 10%, and the paste contained only 20% water, but the thixotropy of the composition increased yield stress has decreased. Also, with increase of CMC additive from 0.6 to 1.8%, a decrease in zeta potential from -48.9 to -36.9 mV and an increase in pH from 7.31 to 9.11 were observed and as results, the viscosity of ceramic paste increased. The thixotropy of the composite increased with increasing CMC percentage. The addition of less than 1%wt PVA changed the flow behavior of the paste to shear-thickening but by reaching 1%wt PVA additive in the paste, the behavior of the paste changed to shear-thinning. Additives By improving the flowability of the ceramic paste, uniformed the mixture of water and solid content of paste and in the printability test, due to the reduction of friction of the paste with nozzle, filaments were placed continuously and had high surface quality and paste printed without clogging. The result of different Particle size distribution of silicon carbide were 6, 16, and 37 micrometer showing that with the increase in particle size distribution, viscosity and yield stress decreased. The yield stress with 37-micron particle size is 3.35 pa, with 16-micron particle size is 12.39pa and with 6-micron particle size is 16.08pa. the apparent density for the sample containing 1%wt pva, 0.6%wt CMC, and 10%wt PEG were measured, 2.09, 1.93, and 1.92 g/cm3, respectively, and the apparent porosity values were measured at 31.73, 41.88 and 44.4%, respectively, for the samples.
