In Situ Preparation of Ti 2 Ni/NiTi Dual‐Phase Alloy With High Wear Resistance and Damping Performance by Additive Manufacturing
Ze Pu, Jingjing Mao, Long Cui, Dong Du, Changyong Chen, Hao Jiang, Liying Sun, Xiebin Wang, Zibin Chen, Kangcheung Chan, Baohua Chang, Ming Li, Chengrui ZhangABSTRACT
Many metallic components are frequently subjected to coupled environments of friction and vibration, stemming from interfacial contact and relative motion between mating parts or external stimuli. Consequently, it is imperative for these components to exhibit a synergy of high wear resistance and superior damping properties. In this study, a Ti 2 Ni/NiTi dual‐phase alloy with exceptional wear resistance and damping performance was in situ alloyed using the electron beam directed energy deposition (EB‐DED) process, employing pure Ti and Ni wires as raw materials. Within the three‐dimensional configuration, the NiTi martensite phase exhibits an island‐like morphology, embedded within a continuous network of the Ti 2 Ni phase, featuring an approximately equal phase ratio. This dual‐phase structure effectively harnesses the respective advantages of the Ti 2 Ni phase and the NiTi martensite phase. In friction scenarios, the hard Ti 2 Ni phase acts as a load‐bearing framework to resist the wear, whereas the NiTi martensite phase can deform to minimize wear and recover from deformation upon heating, demonstrating self‐healing capabilities. Under vibration conditions, the NiTi martensite phase dissipates energy through the movement and rearrangement of twin boundaries, resulting in effective damping. This dual‐phase structure shows promising potential for applications where friction and vibration coexist. Moreover, the phase ratio of Ti 2 Ni and NiTi can be flexibly tailored by EB‐DED technology through the regulation of wire feeding speeds, allowing for the on‐demand balance between wear resistance and damping performance.