Effect of current field on Ti/TiAl interface and mechanical performance

Ti/TiAl gradient materials were prepared by field-activated pressure-assisted synthesis(FAPAS) process. The microstructure, phase composition and fracture morphography of the interface were analyzed by SEM and XRD. The bending strength of the sample was tested by three-point bending test. Meanwhile, finite element analysis with ANSYS code was used to calculate the mechanical properties such as residual stress and deformation. It was shown that fine TiAl particles were formed with FAPAS and maximum bending strength as high as 346 MPa was obtained in the Ti/TiAl interface. The interface were layered gradient structure of TiAl/Ti₃Al/Ti(ss. Al)/Ti. The fracture located in the TiAl-Ti₃Al interface, and showed brittle fracture morphology. The maximum residual stress sited in the TiAl-Ti₃Al interface, which was the position of weakness of the material.