成分梯度对激光立体成形Ti_3Al/TC11连接界面组织和性能的影响

Effect of Component Gradient on Microstructure and Properties of Joining Interface for Ti_3Al/TC11 Alloy by Laser Solid Forming

采用激光立体成形制备Ti3Al/TC11双合金件,研究不同过渡区层数即不同成分梯度时Ti3Al/TC11激光烧结连接界面的显微组织、拉伸性能及显微硬度。结果表明,成分梯度对连接界面的组织形貌影响较大,尤其对TC11侧界面的组织影响更为显著。成分梯度对Ti3Al/TC11试样连接界面显微硬度的平均值影响很小,但对其分布的均匀性影响较大。随着过渡区成分梯度的减小,连接界面显微硬度分布的均匀性提高。具有较小成分梯度即10层过渡区的试样综合性能较佳,这与过渡区层数的增多减小了相邻两层之间的成分梯度、缩小连接界面组织形貌的差异,从而提高了连接界面的完整性有关。

The Ti3Al/TC 11 dual alloy specimens with various layers in the transition zone, that is, with different component gradients in the transition zone, were prepared by laser solid forming. Then the microstructure, tensile properties and microhardness of the joining interface with various layers number in the transition zone were investigated. The results show that the component gradient of the transition zone has a significant effect on the microstructure of the joining interface, especially in the interface on the TCll alloy side. Moreover, the component gradient of the transition zone has almost no effect on the average value of the microhardness for the Ti3Al/TCl 1 joining interface, but it significantly affects the distribution uniformity. With the decreasing of component gradient of the transition zone, the distribution homogeneity of the microhardness is improved. Furthermore, the combination properties of the specimen with 10 layers in the transition zone are better, which is related to the improving integrity of the joining interface due to the smaller component gradient between the adjacent two layers and the smaller differences in the microstructure pattern of the joining interface