Development of high temperature resistant boron added cordierite ceramics

Cordierite-based ceramics use in critical applications due to their low coefficient of thermal expansion, high resistivity and low dielectric coefficient. This study aimed to develop cordierite recipes using colemanite and obtain cordierite ceramics at 1000 – 1100 - 1200 ºC sintering temperatures and ensure their manufacturability with minimum energy consumption. The effect of colemanite as a boron additive was investigated in the reference cordierite recipe on the properties of cordierite ceramics at various temperatures. Phase analysis, microstructure and thermal expansion coefficients of the samples were investigated by XRD, SEM and Dilatometer methods, respectively, and their behavior against heat was determined by DTA/TGA methods. The physical properties of the test samples were characterized by Three-Point Bending and Water Absorption tests. As a result of the findings, it was seen that the strength decreased with the increase in temperature with colemanite ratio, the firing shrinkage for 3% and 5% ratios increased at increasing temperatures, but decreased with increasing temperature. The water absorption values, which are other physical properties, also increased due to the increasing amount of colemanite, while it decreased with the increase in temperature. When the results were examined, it was concluded that the 1% boron additive would significantly reduce the crystallization temperature of the materials in the cordierite stoichiometry and provide a significant benefit in energy saving. Keywords: Boron, Colemanite, Cordierite, Ceramic, Sintering