煤熔渣对SiC-CA6复合材料的侵蚀机制分析

Corrosion mechanism analysis of coal slag on SiC-CA6 composites

采用静态坩埚法,在埋碳气氛中对SiC-CA6复合材料进行了1 500℃保温3 h的抗煤熔渣侵蚀试验,通过XRD、SEM、EDS等分析了煤熔渣对SiC-CA6复合材料的侵蚀机制。结果表明:1)在还原气氛下,SiC-CA6复合材料中未发现明显的侵蚀层,形成的渗透层较薄且比较致密,表明Si C-CA6复合材料具有较好的抗煤熔渣性能。2)煤熔渣对Si C-CA6复合材料的侵蚀主要包括渣层界面处的Si C颗粒被渣中的铁氧化物氧化,以及基质中的CA6与渣中的SiO2、Al2O3、CaO反应生成CAS2。CAS2溶入渣中使得界面处局部区域内的熔煤渣黏度增大,抑制了熔渣向材料内部的进一步渗透。

The coal slag corrosion resistance of SiC-CA 6 composites was tested using the static crucible method under carbon embedded atmosphere at 1500℃for 3 h.The corrosion mechanism of coal slag on SiC-CA 6 composites was studied by means of XRD,SEM and EDS.The results show that:(1)in the reducing atmosphere,no obvious corrosion layer is found in the SiC-CA 6 composites;the formed permeation layer is relatively thin and dense,indicating that SiC-CA 6 composites have good slag corrosion resistance;(2)the corrosion mechanism of coal slag on SiC-CA 6 composites mainly includes two aspects:the oxidation of SiC particles at the slag/sample interface by iron oxide in the slag and the reaction of CA 6 in sample matrix with the SiO 2,Al 2O 3 and CaO in the slag to form CAS 2;the formed CAS 2 can dissolve into the slag and increase the viscosity of the local slag at the slag/sample interface,therefore suppressing the further penetration of the slag into the material.