Parameters Affecting Pressureless Sintering of α'-Sialons with Lanthanide Modifying Cations

Abstract

ABSTRACTμ-silicon nitride forms a range of solid solution Mx(Si,Al)12(0,N)16 where x = 2 and M is Li+, Ca2+, y3+ or certain lanthanide cations. This paper reports the formation of Ln-α'-sialons by the reaction of Si3N4 with AIN and Ln2O3 where Ln=Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y. Transformation reactions of Nd, Sm, Gd, Ho, Er and Y cations occurring during liquid phase pressureless sintering are reported. The effects of the volume and viscosity of the liquid phase and the amountof secondary N-melilite on sintering are discussed.