<b>Microstructure and Properties of Ti-6Al-4V/Ni-Ti Heterogeneous Structure Materials with Cu-Ni Interlayer via Multi-Wire Arc Additive Manufacturing</b>

This study employs Multi-Wire Arc Additive Manufacturing (M-WAAM) to fabricate Ti-6Al-4V/Ni-Ti heterogeneous structure materials. The results show that the incorporation of the Cu-Ni interlayer effectively suppresses the formation of brittle Ti-Ni intermetallic compounds, thereby enhancing the interfacial bonding strength. This improvement is attributed to the formation of stable Ti-Cu and Ti-Ni-Cu phases at the interface. Furthermore, the microhardness within the interlayer region exhibits a substantial increase, reaching ~ 570 HV_0.2, which indicates enhanced material strength at the interface. The average ultimate tensile strength of the material is measured at 279.9 ± 15 MPa, with a strain of 5.6 % ± 2 %. The introduction of the Cu-Ni interlayer thus provides an effective approach for the design and fabrication of heterogeneous structure materials. This approach not only addresses the challenge of interfacial integrity but also offers considerable potential for the development of large-scale heterogeneous components in industrial applications, such as aerospace and biomedical fields.本研究采用多丝电弧增材制造（Multi-Wire Arc Additive Manufacturing, M-WAAM）技术制备Ti-6Al-4V/Ni-Ti异种结构材料。研究结果表明，引入Cu-Ni夹层可有效抑制脆性Ti-Ni金属间化合物的生成，进而提升界面结合强度。该性能提升归因于界面处稳定的Ti-Cu及Ti-Ni-Cu相的形成。此外，夹层区域的显微硬度显著提升，可达约570 HV₀.₂，表明界面处材料强度得到增强。该材料的平均极限抗拉强度为279.9 ± 15 MPa，断裂应变为5.6 % ± 2 %。由此可见，Cu-Ni夹层的引入为异种结构材料的设计与制备提供了有效途径。该方法不仅解决了界面完整性难题，还为航空航天、生物医学等工业领域的大型异种构件开发提供了可观的应用潜力。