分别对Al- TiO2体系、A1 -V2O5体系、Al-V2O5 -TiO2体系以及Al- V2O5 - TiO 2 - CaO 体系单位 质量反应热( q, J/g)进行了计算.考察了单位质量反应热对实验结果的影响.利用XRD物相分析仪、SEM 扫描电镜以及ICP对合金进行了系统的分析.结果表明:Al - V2O5 - TiO2 - CaO体系的单位质量反应热小于 2 700 J/g,发热量不足,反应不能靠自热进行,需要对体系进行补充热量才能保证自蔓延反应顺利进行;CaO的加入会降低体系的单位质量反应热.合金的主要物相为D、Al金属间化合物、Al2O3及硅铁化合物. 合金微观组织结构为基体相、板条状β相以及不规则的Al2O3夹杂相,单位质量反应热对合金中含硅相的尺 寸及分布有较大影响.随着单位质量反应热的增加,合金中Ti的含量呈下降趋势,合金中的铝呈上升趋势,V、Fe、沿元素含量(质量分数/%)随单位质量反应热的增加基本保持不变.制备合金中Al的质量分数最 低为9.35%, Fe最低为2. 17%, Si最低为0.78%, V 最高含量为4. 30%.
The reaction heats per unit mass for Al -TiO2, Al - V2O5, Al - V2O5 - TiO2 and Al - V2O5 - TiO2 - CaO systems were calculated. Effect of addition of aluminum powder and KClOs on preparation of Ti - Al - V alloy was studied. The alloy was analyzed by XRD, SEM, Inductively Coupled Plasma Emission. The results showed that the heats per unit mass of Al - V2O5 -TiO2 - CaO system is less than 2 700 J/g, indicating that the reaction cant occur spontaneously. Addition of CaO decreases the reaction heat per unit mass of the system. The main physical phases of the alloy prepared by the thermite process are Ti - Al intermetallic compound, Al2O3 and Fe - Si compounds. The reaction heats per unit mass has a great effect on the the size and distribution of silicides. Content of titanium in the alloy decreases, with the content of aluminum increases, while the contents of vanadium, iron and silicon changes a litde with increase of the reaction heat. The lowest contents of Al, Fe, Si in the alloy are 9. 35% , 2. 17% , 0. 78% . The highest content of vanadium is 4. 30% .