Sol-gel Preparation and Infrared Radiation Property of Boron-substituted Cordierite Glass-ceramics

Boron for aluminum substitution in the cordierite structure has been examined by sol-gel preparation of different samples along the compositional junction Mg2Al4-xBxSi5O18 with x=0, 0.5, 1, 1.5. By increasing the x value from 0 to 1.5 the crystallization behavior changed accordingly. Proper amount B2O3 doping can promote the sintering of amorphous cordierite gel, effectively restrain the precipitation of μ-cordierite and enhance the crystallization of α-cordierite. The substitution of B3+ for Al3+ in cordierite crystal structure can effectively improve the near-infrared spectral emissivity of this cordierite based glass-ceramics.