Al_4SiC_4的制备及其对镁碳砖抗氧化性能的影响

Synthesis of Al_4SiC_4 and Its Effect on the Anti-oxidation Behavior of Magnesia-carbon Bricks

镁碳砖中碳的氧化是影响其使用寿命的主要原因。利用真空烧结制备的Al4SiC4粉体作为抗氧化剂提高镁碳砖的抗氧化性。加入Al4SiC43%~5%时,碳损失量降低50%~60%（1500℃,6h）。Al4SiC4能还原被氧化的碳,同时将自身的碳作为游离碳加入到镁碳砖中补充碳源。Al4SiC4分解生成的Al2O3、SiC与MgO反应最终生成镁铝尖晶石和镁橄榄石在砖体表面形成保护层防止进一步氧化。

Oxidation of carbon is the main problem in magnesia-carbon bricks.Al4SiC4 powder was prepared by vacuum sintering in vacuum sintering furnace.It can reduce carbon which was oxidized.The carbon loss of specimens adding Al4SiC4 decreased by 50%-60%（1500 ℃,6 h） with additiond of 3-5% Al4SiC4.The carbon of Al4SiC4 became graphitic carbon to resist oxidation.The Al4SiC4 decomposed to Al2O3 and SiC which reacted with MgO formed magnesium aluminate spinel and forsterite.The protective layer was formed to prevent oxidation.