Crack resistance of corundum refractories over a wide range of temperatures

Conclusions The ultimate bend strength _bnd and the critical stress intensity factor K_lc of a group of corundum refractories were determined over a wide range of temperatures. It was shown that the temperature dependences of _bnd and K_lc have a similar nature. In the refractories having the usual porous structure, the rate of decrease of K_lc with increasing temperature is less than that of _bnd. Owing to this, the coefficient of crack resistance K_t of the refractories increases at high temperatures.The refractories having a porous-fissured structure, exhibit an almost identical reduction of _bnd and K_lc with increasing temperature and the magnitude of K_t increases very insignificantly.Translated from Ogneupory, No. 3, pp. 8–11, March, 1987.