Sintering of calcium aluminate mixes

Measurements of initial sintering shrinkage of mixes of CaAl4O7 and CaAl2O4 are reported in the temperature range 1360-1420(degree)C. The particle size chosen was 45 (mo)mand the mix proportions were 5:8, 4:10, and 3:11 by weight of CaAl4O7 and CaAl2O4. The soaking periods were from 10 to 180min. The time dependence of shrinkage showed that volume diffusion is the dominant mechanism in the sintering of mixes. At any temperature and sintering time, the shrinkage and densification increased with increase in CaAl2O4 content. The mixes produced a two phase system and the activation energy for the sintering was 251.6 kcal mol(-1) BCT/212