Densification Peculiarities of Transparent MgAl2O4 Ceramics—Effect of LiF Sintering Additive

Abstract

A new method of doping of spinel nanopowders with LiF sintering additive has been proposed, consisting in its introduction via solution technology, which leads to improved sinterability of the ceramic. The effect of LiF doping on densification behavior, microstructure, and optical and mechanical properties of hot-pressed MgAl₂O₄ ceramics has been studied. Samples of MgAl₂O₄ optical ceramics with density close to that theoretically achievable have been produced by hot pressing of 0.5 wt % LiF-doped nanopowders at 1600°C for 1 h. It has been shown that addition of LiF changes crack propagation in spinel ceramic from transgranular to intergranular.