Synthesis of CA 6 /AlON composite with enhanced slag resistance

Different amounts of AlON have been introduced in calcium hexaaluminate (CA 6 ) using two approaches, that is, one-step and two-step methods, to improve the slag resistance of CA 6 . A one-step method can directly sinter the mixtures combining Al 2 O 3 , CaCO 3 , and Al in flowing nitrogen, in which AlON clusters are always formed because of the poor wettability of Al by Al 2 O 3 , leading to the high porosity of CA 6 /AlON composite. In a two-step method, CA 6 and AlON are prepared separately and then mixed and sintered in flowing nitrogen. Compared with the sample prepared by the one-step method, CA 6 and AlON in composite by the two-step method are more uniformly distributed, and the optimized amount of AlON added is 10wt%. The slag corrosion and penetration test shows that the CA 6 /AlON composite using the two-step method exhibits superior slag corrosion protection. The promoted effect of AlON on slag penetration and corrosion resistance is also discussed.