Effect of Ni Interlayer on Cavitation Erosion Resistance of NiTi Cladding by Tungsten Inert Gas (TIG) Surfacing Process

Abstract

The NiTi cladding with/without Ni interlayer was prepared on stainless steel (SS) by tungsten inert gas (TIG) surfacing process, aiming at achieving good cavitation erosion resistance. The ranking according to the cavitation erosion resistance is NiTi plate > NiTi–Ni–TIG cladding > NiTi–TIG cladding > SS. The better cavitation erosion resistance of NiTi–TIG and NiTi–Ni–TIG claddings than SS substrate is due to their higher micro-hardness and superelasticity. Furthermore, the existence of Ni interlayer can decrease the amount of brittle intermetallic compounds, such as Fe2Ti, and inhibit the crack generation, which results in the higher cavitation erosion resistance of NiTi–Ni–TIG compared with NiTi–TIG cladding. Thus, the cavitation erosion resistance of NiTi cladding prepared by TIG surfacing process can be improved by employing Ni interlayer.