THE EFFECT OF SESQUIOXIDES OF 3d-TRANSITION ELEMENTS ON THE STRENGTH OF SYNTHETIC MULLITE AND MULLITE-BASED MATERIALS'

摘要

Mullite synthesized from alumina and silica with the sesquioxide of a 3d-transition metal added (Me = Sc, Ti. V, Cr, Mn, and Fe) is capable of forming solid solutions of composition Al_(6-x)Me_xSi_2O_(13). It is shown, using data obtained by methods of x-ray phase analysis, electron paramagnetic resonance, infrared spectroscopy and magnetic susceptibility, that the aluminum atoms located at octahedral positions of the mullite lattice can be isomorphously replaced by Me metals. The effect of this replacement on the strength of mullite and mullite-based ceramics is considered.