碳含量对Ti-11Al合金的铸态微观组织的影响

Effect of Carbon Content on Microstructure of As-Cast Ti-11Al Alloy

采用反应自生法制备颗粒增强不同含 C量的 Ti- 11Al合金基复合材料。利用 X射线衍射、OM和 SEM研究复合材料的微观组织 ,结果表明 :当合金中的 C含量增加到一定程度后 ,合金的基体由 α+α2 两相变为单相 α2 基体 ;颗粒相由单一的 Ti C变为 Ti3Al C和 Ti C两相 ;颗粒形貌由短板条状向不发达树枝晶和等轴晶状发展。

WT5BZ]Particulate reinforced Ti 11Al matrix composites with different C content were fabricated by using a reaction synthesis method Microstructures of the composite were investigated by XRD,OM and SEM The results indicate that the matrix of alloy is transformed to single α 2 phase from α+α 2 two phases, and reinforcements become Ti 3AlC and TiC two phases from single TiC phase as C content increasing to a critical value Also with the increasing of C content, the morphology of reinforcements are changed from short lath shape to undeveloped dendrite and equiaxed dendrite In the meantime, the main reasons of microstructure transformation were analyzed in the light of phase diagrams