Effect of component gradient on microstructure and properties of joining interface for Ti₃Al/TC11 alloy by laser solid forming

The Ti₃Al/TC11 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 TC11 alloy side. Moreover, the component gradient of the transition zone has almost no effect on the average value of the microhardness for the Ti₃Al/TC11 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.