Low-temperature Fabrication Of Organic-ceramic Hybrid Materials

Ceramic industry has the shortcoming of the large energy consumption, therefore, reducing the firing power consumption is an important part of decreasing production cost to promoting the economic efficiency. There have been many ways of reducing the power cost of firing, but lowering the temperature of fire the green body to achieve low-temperature sintering is the fundamental way to solve the problem of high energy expenditure. Adding polymer with high viscosity into green body at the final stage of densification process as sintering aid to accelerate solid mass transferring, lower the densifying temperature by liquid phase sintering, so organic-ceramic hybrid materials could be fabricated at low temperature.This work prepare the alumina/phenolic resin mixed powders by blending, the uniform zirconia/phenolic resins precursor powder by sol-gel process and the zinc oxide/phenolic resin by co-precipitation method. It is the first time to use the SPS pulse rapid heating sintering technology to obtain high-performance porous alumina ceramics and densified zirconia-organic, zinc oxide-organic ceramic hybrid materials at low temperature. We have analyze the influence of the raw material proportion and synthesis technology to the structure and organized properties of the product, and discussed the sintering mechanism. Focusing on the effect of sintering temperature, heating rate, holding time and sintering pressure on the preparation of materials. [Optimizing condition for preparing porous alumina ceramic at low temperature is as followed:organic matter content of 10%, maximum temperature of 1100℃, heating rate of 100℃/min, pressure of 35 MPa. Under the best condition, the porosity of the samples is 30.67%, the density:0.8, average pore size:62.8nm, high flexural strength 188MPa.SPS is the way with great heating rate and short holding time to reduce the length of time for sintering ceramic greatly, whose high heating rate and cooling rate lead to high activity of reactants before and after the reaction. It is conducive to the densification of ceramics, to decrease the sintering temperature for certain degree, to make the reaction proceeds at relatively low temperature, thus effectively restraining the decomposition of organic matter. Optimized reaction condition of the zirconia/organic hybrid ceramics is:sintering temperature of 400℃, heating rate of 100℃/min, holding time of 10min, sintering pressure of 40MPa. zirconia ceramics with organics as the binder can be prepared by the optimum technology.In this paper, we discuss the conditions required for the formation of liquid phase by phenolic resin in the process of zinc oxide ceramics, preliminarily prepare organic-zinc oxide ceramic hybrid materials with certain strength and structure. But the distribution of organic matter in the samples is extremely uneven, only in the local area it could play bonding effect.