On the effects of LiF on the synthesis and reactive sintering of gahnite (ZnAl2O4)

The effects of LiF on the synthesis and reactive sintering of polycrystalline gahnite (zinc aluminate spinel, ZnAl2O4) were studied using XRD, high-temperature simultaneous thermal analysis and a spark plasma sintering (SPS) apparatus. It was demonstrated that the LiF reduces the onset of synthesis by about 200 °C and plays an important role in the densification process. SPS consolidation of a LiF-doped ZnO-Al2O3 mixture under an applied pressure of 150 MPa and at a sintering temperature of 1100 °C for 20 min generated fully dense gahnite with adequate transparency and mechanical properties.