Abstract
Electrochemical tests and surface analysis were applied to study the corrosion behavior and passive film characteristics of three-dimensional-printed NiTi shape memory alloys fabricated by laser-powder bed fusion (L-PBF) in artificial saliva at 37 °C. The passivity of L-PBF NiTi shows to be influenced by the process parameters and resulting morphological and physicochemical surface properties. The results show that the defects at the surface of L-PBF NiTi can promote the passivation rate in the early stages of exposure but a slowly formed passive film shows the best corrosion protection. The thickness of the passive film is positively correlated with its corrosion protective performance. The L-PBF NiTi alloy prepared at a linear energy density of 0.2 J·m−1 and volumetric energy density of 56 J·mm−3 shows the least defects and best corrosion protection. An outer Ti-rich and inner Ni-rich dense passive film could be also obtained showing higher corrosion resistance. Graphic Abstract: [Figure not available: see fulltext.]
Original language | English |
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Pages (from-to) | 3114-3129 |
Journal | Rare Metals |
Volume | 42 |
Issue number | 9 |
DOIs | |
Publication status | Published - 2023 |
Keywords
- Artificial saliva
- Corrosion resistance
- Laser-powder bed fusion (L-PBF)
- NiTi
- Passive film