Sintering Mechanisms of LiF-Doped Mg-Al-Spinel

A model system of MgAl-spinel doped with 5 similar to wt% lithium fluoride was examined using transmission electron microscopy and X-ray diffraction to verify three major processes during sintering, as postulated in literature. Densification and sintering is facilitated by the addition of LiF that forms different transient phases, which are detectable at various stages of the densification process. The postulated mechanisms (i) wettingdewetting, (ii) incorporation of oxygen vacancies, and (iii) dissolutionreprecipation could be verified in this model system; however, being effective at different temperature regimes.