Resistive thermal fusion interface of a novel excellent balanced-performance laminated Ti-5Al-2.5Sn / Ti-6Al-2Zr-1Mo-1V dissimilar titanium alloys

Ti-5Al-2.5Sn (TA7) and Ti-6Al-2Zr-1Mo-1V (TA15) alloy are widely utilized in the aerospace industry for its high specific strength, exceptional corrosion resistance, and excellent weldability. Nonetheless, notable performance variations exist among various types of titanium alloys. TA7 titanium alloy is known for its high ductility, although its strength falls short compared to TA15 alloy. On the other hand, TA15 alloy boasts high strength but is characterized by low ductility. A novel laminated TA7/TA15 dissimilar titanium alloy component was successfully created for the first time using resistive thermal fusion interface additive manufacturing technology. This innovative approach resulted in a material with exceptional mechanical properties, combining high strength and high ductility in a single component. During the deposition process, TA7 wire and TA15 wire are fused at the interface by strictly controlling the current and feeding rate, while the inner parts of the wire remain in unmelted state. The thickness of the interface transition zone between TA7 and TA15 is 36 mu m. The chemical composition in the transition zone exhibits a gradient change. The interface between the two types of titanium alloys is completely fused, and no defects are observed at the interface. The tensile strength of the laminated material achieved 1080 MPa, while the elongation reached 13.83 %. These results clearly demonstrate the successful integration of the high strength of TA15 alloys with the high toughness of TA7 alloys in the novel laminated titanium component. The mixed law theory and finite element analysis have verified that the excellent balanced performance is mainly due to the combination of the excellent properties of TA15 alloys and TA7 alloys, as well as the perfect fusion at the interface between the two titanium alloys. Hence, this study offers a promising method for producing high-performance laminated thin-walled titanium alloy components such as blades and fuel tanks applied in the aerospace field.