Effect of sintering additives on the oxidation behavior of Si3N4 ceramics at 1300 °C

摘要: Abstract This paper describes the results of systematic investigation oxidation behavior Si 3 N 4 based ceramics. The tests were carried out at 1300 °C for 2000 h in a high-temperature dry air environment. specimens tested include following: (a) S-1: added 8 mass% Y 2 O , (b) S-2: /SiC 3, (c) S-3: 5 mass% and 3 mass% Al (d) S-4: 3. Several interesting conclusions obtained as follows: (1) thicknesses oxidized layer S-3 S-4 much thicker than S-1 S-2, (2) kinetics S-2 obeyed parabolic law on whole, while those had break, (3) yttrium (Y) concentration under decreased significantly. Y-decreased zone was defined diffused layer. layers samples very large. (4) Primarily, crystalline phases SiO 7. (5) effect SiC composition small.