Sintering Performance of MgAl2O4 Spinel with Various Al2O3 Content

摘要

Magnesium aluminate spinel specimens with various Al_2O_3 content were prepared. Sintering performance and microstructure of different kinds of MgAl_2O_4 spinel were studied. It is found that the sintering of materials becomes more difficult with the increase in their Al_2O_3 contents. Corundum begins to precipitate from the magnesium aluminate spinel with 85wt% Al_2O_3 at 1400°C. However, with further increase in the sintering temperature, the corundum dissolves into magnesium aluminate spinel(above 1600°C). The precipitation and solid solution of corundum hinder the sintering of materials. In alumina-rich spinel, if the content of Al_2O_3 in alumina-rich spinel materials is more and the content of CA_6 is also more. At the same time CA_6 crystal is bigger in the alumina-rich spinel.