Effect of α-Al2O3 on in situ synthesis low density O′-sialon multiphase ceramics

Improved oxidation resistance properties of Si 3 N 4 /O′–SiAlON composite ceramics by a repeated sintering method

“…In the present work, Si 3 N 4 /O′–SiAlON composite ceramics were subjected to oxidation in air, which typically belonged to passive oxidation. On the basis of thermodynamic analysis, both Si 3 N 4 and O′–SiAlON underwent oxidation, and their reaction formulas () and () were as follows 21,22 : $$\begin{equation} \def\eqcellsep{&}\begin{array}{l} {\rm{S}}{{\rm{i}}_{\rm{3}}}{{\rm{N}}_{\rm{4}}}\left( {\rm{s}} \right) + 3{{\rm{O}}_{\rm{2}}}\left( {\rm{g}} \right) \to {\rm{3Si}}{{\rm{O}}_{\rm{2}}}\left( {\rm{s}} \right) + 2{{\rm{N}}_{\rm{2}}}\left( {\rm{g}} \right)\\[7pt] {{\Delta}}G_{\rm{1}}^{\rm{0}} = - {\rm{1997}}{\rm{.5}} + {\rm{0}}{\rm{.21213}}T\\[7pt] {{\Delta}}{G_{\rm{1}}} = {{\Delta}}G_{\rm{1}}^{\rm{0}} + RT{\rm{ln}}\dfrac{{{P^{\rm{2}}}\left( {{{\rm{N}}_{\rm{2}}}} \right)}}{{{P^{\rm{3}}}\left( {{{\rm{O}}_{\rm{2}}}} \right)}} \end{array} \end{equation}$$ …”

“…In the present work, Si 3 N 4 /O′-SiAlON composite ceramics were subjected to oxidation in air, which typically belonged to passive oxidation. On the basis of thermodynamic analysis, both Si 3 N 4 and O′-SiAlON underwent oxidation, and their reaction formulas ( 5) and (6) were as follows 21,22 :…”

A novel method to fabricate porous single phase O’-sialon ceramic and improve its mechanical property

“…However, the bending strength was associated closely with both porosity and pore size. Based on the empirical formula of porous ceramic described by Ryshkewitch as follows Equation (1) [28]:…”

“…Furthermore, most of the scholars devoted to investigating porous α-SiAlON, β-SiAlON and multiphase sialon ceramics [17][18][19], which mainly intended to pursue mechanical properties and dielectric property as well as thermal conductivity. Additionally, in the case of the study of O'-sialon ceramics, they mostly referred to multiphase ceramics with other additives, such as TiO 2 /(O'+β')-sialon ceramic [20], O'-sialon/Si 3 N 4 ceramic [21], and O'-sialon/TiC ceramic [22]. However, there were no works on the porous single phase O'-sialon ceramics.…”

Synthesis of SiAlON‐type compounds by carbothermal reduction and nitridation of nanoparticulate geopolymers

“…6 O-SiAlON (Si 2−x A1 x O 1+x N 2−x where 0 < x ≤ 0.4) itself exhibits good oxidation resistance to 1600 • C and is being considered as a most promising material, especially as a thermal barrier coating for high temperature applications. 7,8 X-SiAlON has a similar structure to that of mullite and a narrow solid solution range between Si 3 N 4 and mullite 9 with the composition ranging from SiAlO 2 N to Si 16.9 Al 22.7 O 48.8 N 11.6 . 10 X-SiAlON possesses good oxidation resistance because it has the highest oxygen content among the other compounds and Si 3 N 4 in the quaternary system.…”