采用铝热自蔓延法制备低氧高钛铁合金

摘要

以金红石、钛精矿和Al为原料采用铝热自蔓延法制备出低氧高钛铁合金.研究不同反应体系的相关热力学,考察配铝量对铝热自蔓延熔炼效果的影响,采用XRD,SEM以及化学分析等技术对高钛铁合金进行表征.研究结果表明:反应体系的绝热温度大于l 800K,反应能自我维持进行；铝还原TiO2反应的单位质量热效应较低,铝还原铁氧化物反应的单位质量热效应较高;合金主要由TiFe2,Fe,TiO2和Al2O3等相组成,氧化物夹杂相的存在是合金中氧含量高以及合金微观缺陷存在的直接原因;合金中氧含量最低为2.62％；钛、铝、铁和硅质量分数分别为61.58～66.27％,4.05％～9.20％,16.15％～20.53％及2.78％～3.82％.%Rutile, ilmenite and Al powder were used to prepare high titanium ferrous alloy by thermit reduction-SHS(seli -propagating high-temperature synthesis). The thermodynamic of the relative reaction systems was studied, and the effects of the proportion of Al on the thermit reduction-SHS melting process were investigated. The high titanium ferrous alloys were characterized by XRD, SEM and chemical compositions analysis technologies. The results indicate that the adiabatic temperatures of all reaction systems are higher than 1 800 K, so that all the reactions can keep on carrying on by themselves. The unit reaction heat is low when Al reduces TiO2, but the unit reaction heat is higher when Al reduces iron oxides. The high titanium ferrous alloys mainly consist of TiFe2, Fe, TiO2 and Al2O3. The oxide inclusions exist in the alloy, which directly results in the high oxygen content and micro-structural defects in the atloys. The lowest oxygen content is 2.62% in the alloy, and the contents of titanium, aluminum, ferrous and silicon in the alloy are 61.58-66.27%, 4.05%~9.20%, 16.15%~20.53% and 2.78%~3.82%, respectively.