α/β-sialon having improved sintering activity and high edge strength

A sintered molded article comprising a ceramic comprising α/β-sialon having a grain boundary phase, wherein the grain boundary phase contains at least TiN formed in situ as an additional phase by sintering a starting material without pressure or with gas pressure, the starting material comprising 75 to 92 wt.-% Si3N4, 3 to 15 wt.-% of at least one oxide of the rare earths and/or Y2O3, 1 to 15 wt.-% of an aluminum compound, comprising AlN and, optionally, Al2O3 in a weight ratio of AlN:Al2O3 greater than 4:1, 0.1 to 3 wt.-% of TiO2, and CaCO3, wherein the sum of the starting substances corresponds to 100 wt.-%, wherein the sintered molded article has a final density of at least 99%, wherein in the sintered state, in the interior of the sintered molded article, the proportion of α-sialon with reference to the entire sialon phase amounts to 20 to 70 vol.-%, and the proportion of β-sialon amounts to 80 to 30 vol.-%, and wherein the surface of the sintered molded article, in the sintered state, amounts to a proportion of α-sialon with reference to the entire sialon phase from 55 to 95 vol.-%, and the proportion of β-sialon amounts to from 5 to 45 vol.-%.