Microstructure and corrosion behavior of laser processed NiTi alloy
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Date
2015
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier Ltd
Abstract
Abstract Laser Engineered Net Shaping (LENS™), a commercially available additive manufacturing technology, has been used to fabricate dense equiatomic NiTi alloy components. The primary aim of this work is to study the effect of laser power and scan speed on microstructure, phase constituents, hardness and corrosion behavior of laser processed NiTi alloy. The results showed retention of large amount of high-temperature austenite phase at room temperature due to high cooling rates associated with laser processing. The high amount of austenite in these samples increased the hardness. The grain size and corrosion resistance were found to increase with laser power. The surface energy of NiTi alloy, calculated using contact angles, decreased from 61 mN/m to 56 mN/m with increase in laser energy density from 20 J/mm2 to 80 J/mm2. The decrease in surface energy shifted the corrosion potentials to nobler direction and decreased the corrosion current. Under present experimental conditions the laser power found to have strong influence on microstructure, phase constituents and corrosion resistance of NiTi alloy. © 2015 Elsevier B.V.
Description
Keywords
Austenite, Corrosion resistance, Corrosive effects, Hardness, Interfacial energy, Manufacture, Microstructure, Additive manufacturing technology, Corrosion potentials, Experimental conditions, Hardness and corrosion, Laser energy density, Laser engineered net shaping, Laser process, NiTi alloys, Corrosion, alloy, nickel, titanium, titanium nickelide, chemistry, corrosion, laser, radiation dose, radiation response, surface property, Alloys, Dose-Response Relationship, Radiation, Lasers, Nickel, Radiation Dosage, Surface Properties, Titanium
Citation
Materials Science and Engineering C, 2015, 57, , pp. 309-313