Impurity formation mechanism of silicon carbide crystals smelted by Acheson process  

作　　者：Dong Feng Hong-qiang Ru Xu-dong Luo Jie-gang You Ling Zhang 

机构地区：[1]School of Materials and Metallurgy,University of Science and Technology Liaoning,Anshan 114051,Liaoning,China [2]Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education),Institute of Advanced Ceramics,School of Materials Science and Engineering,Northeastern University,Shenyang 110819,Liaoning,China [3]Liaoning Institute of Science and Technology,Benxi 117004,Liaoning,China

出　　处：《Journal of Iron and Steel Research International》2024年第6期1367-1375,共9页

基　　金：supported by the National Natural Science Foundation of China(Grant No.U20A20239).

摘　　要：In order to further promote the application of SiC refractories in modern steel metallurgy,the occurrence forms and formation mechanism of impurities in SiC crystals smelted by Acheson process were investigated.The techniques of inductively coupled plasma-atomic emission spectrometry,X-ray diffraction,and scanning electron microscopy were combined to examine the types and occurrence forms of impurities in smelted SiC crystals.The results showed that the main impurities in the SiC are free Si,free C,oxides(CaO·Al_(2)O_(3)·2SiO_(2),3Al_(2)O_(3)·2SiO_(2),CaO·SiO_(2) and SiO_(2))and alloy phases(Fe_(x)Si_(y),Fe_(x)Si_(y)Ti_(z) and Fe_(x)Al_(y)Si_(z)).The formation process of impurities during the smelting of SiC can be described as follows:At high temperature,the SiO_(2) and Fe,Ti related oxide impurities present in the raw materials are reduced to Si,Fe,and Ti metal melts.After the reduction process,the free Si,Fe_(x)Si_(y) and Fe_(x)Si_(y)Ti_(z) are precipitated from the melt during cooling.Free Si primarily exists in aggregated form within the SiC crystal,while the alloy phase is predominantly found at the interface between SiC and free Si,with Fe_(x)Si_(y)Ti_(z) embedded within FexSiy.Towards the end of the cooling process,other impurity oxides such as Al_(2)O_(3),CaO,and some unreduced SiO_(2) solidify to form calcium-aluminum-silicate glass phases,predominantly located between SiC grains.The remaining C from the reaction is mainly dispersed as free C within the SiC crystal and at the interface between SiC and free Si.

关 键 词：Impurity element Formation mechanism Smelted SiC crystal SiC refractory Occurrence form 

分 类 号：TG1[金属学及工艺—金属学]