Analysis of Oxidation Properties of Silicon-based Ceramics

Ceramics are refractory materials that contain oxides as the main component, and they have been used in harsh environments such as steel, glass manufacturing, coal gasification, and other fields. There have been many reactions involving refractory materials and various gases and slags. Reported. In addition, non-oxide ceramics, namely silicon carbide (SIC) and silicon nitride (Si3N4), are superior to metal materials and oxide ceramics due to high-temperature strength and creep resistance, and are therefore large materials for high-temperature equipment in high-temperature combustion environments. has hope. Therefore, a great deal of research has recently been conducted on high-temperature oxidation and molten salt corrosion.

In the high-temperature combustion atmosphere, SIC and Si3N; etc. silicon-based ceramics show a low diffusion coefficient in the oxide protective film (5102) formed on the surface under conditions of higher oxygen partial pressure and can form a dense protective film. Excellent oxidation resistance. However, when the oxygen partial pressure is low, the oxidation property of the silicon-based ceramic is changed from the diffusion of D to the protective oxidation, which dictates the full reaction rate, to the active oxidation that generates 510 gas, and thus the oxidation resistance is lost. These factors can be divided externally, such as ladle enclosures, preheaters, and other internal factors directly related to the wear of the refractory material.

This article also introduces an interesting point of view of these factors: "Because the workshop is different and the characteristics are different, each factor may play a bigger or smaller role in the workshop." All parties must carefully examine the controls in these tests. The refractories inspector's point of view of the workshop and even if it is leased, should not be used if it is not the product that the user likes.