Desenvolvimento de cerâmicas com alta sinterabilidade à base de Nano Alumina reforçada com CBC produzidas por tape casting

Abstract

The current trend in the research and manufacture of new advanced and structural ceramics seems to favor the use of high purity and ultrafine powders combined with shorter sintering time and lower sintering temperature. Compositions with oxides aides (Cu2O, CuO, TiO2, MgO, B2O3, SiO2, K2O, Na2O, Li2O, ZrO2, ZnO) and the sugarcane bagasse ashes waste (CBC) were prepared with alumina to evaluate the effect of the sintering, density, hardness and microstructural. Thereafter ceramic tapes were produced by tape casting with the most promising formulation. Almost all of the composites showed densification below 1100 ° C. Higher density values (~ 95%) were obtained for compositions based respectively on borosilicate (F3 and F7) and soda lime glass (F8) containing Na on the precursor in powder, and F1, F2, F3 having TiO2 and Cu2O as precursors, and finally the composition with 10% of the ash from the sugarcane bagasse waste. Samples F5 (based on K), F9 (without K or Na in the powder precursor of glass) and F4 presented irregular morphology with the presence of intergranular porosity. The compositions F6, F7 and F8 presented uniform morphology corresponding to densification. And finally, from the mixture of alumina with CBC (AR) waste with addition of reinforcing particles and sintered at 1200ºC was chosen for the production of ceramic tapes. The ceramic suspension showed a decrease in viscosity with increasing shear rate, which characterizes a pseudo plastic behavior, allowing the production of tapes with homogeneous and flat surfaces. The average from the bending test value was 20.14 MPa for the 6-layer laminates.