Research on Oxidation Resistance of SiAlON bonded Silicon Carbide Refractories to High Temperature Steam
SiAlON bonded Silicon Carbide products with the dimension of 230×114×65mm were produced by following the production process of mixing, molding and nitriding sintering, by using silicon carbide grains silicon carbide fine powder, silica powder and alumina micro powder as the main raw materials.Steam oxidation resistance of SiAlON bonded Silicon Carbide material at 900 ℃ was tested according to ASTM-C863 after 100 h, 200 h, 300 h, 400 h and 500 h respectively.Phase composition and microstructure before and after oxidation were analyzed by means of XRD and SEM.Results indicate that there is continuous increase of volume expansion and weight change on materials with the oxidation time.After 100 h of oxidation, a small amount of cristobalite can be observed in the materials, which comes directly from the oxidation of Silicon Carbide and SiAlON or from the crystallization of glass phase.Meanwhile, alumina is released from SiAlON after its oxidation into silica.After 300 h of oxidation, an increased content of cristobalite as well as a small amount of mullite can be noticed.When it comes to 500 h of oxidation, a significant increase of mullite content can be seen and the oxidation is still incomplete.Based on the above,conclusions can be reached that: At the early stage of oxidation, the steam oxidation of SiC and β-Sialon is the main cause of volume expansion of SiAlON bonded Silicon Carbide material.While at the later stage, the sustained formation of mullite, which is from the reaction between oxidation product silica oxide and alumina released out of SiAlON during oxidation, is the main contribution to the continuous volume expansion of the material.
SiAlON bonded silicon carbide steam oxidation silica alumina mullite
ZHANG Xinhua WANG Jiaping HUANG Zhigang LIU Yun WEN Biao CHANG Cheng
Sinosteel Luoyang Institute of Refractories Research Co.,Ltd.,Luoyang 471039,China Sinosteel Luoyang Institute of Refractories Research Co.,Ltd.,Luoyang 471039,China;State Key Laborat
国际会议
西安
英文
1-4
2016-09-20（万方平台首次上网日期，不代表论文的发表时间）