Enhanced wear resistance of NiTi alloy by surface modification with Nb ion implantation

Yan Li^1,2，Fei Zhang¹，Ting-Ting Zhao^1,3，Ming Tang¹，Yong Liu⁴

1. School of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics2. Beijing Key Laboratory for Advanced Functional Materials andThin Film Technology, Beijing University of Aeronautics and Astronautics3. Key Laboratory of Aerospace Advanced Materials and Performance (Beijing University of Aeronautics and Astronautics), Ministry of Education4. School of Mechanical and Aerospace Engineering, Nanyang Technological University

摘 要：Niobium ion implantation is found to significantly decrease the friction coefficient and improve wear resistance of NiTi shape memory alloy. Scanning electron microscope（SEM） observations indicate that surface grooves formed on NiTi during the mechanical polishing are removed after Nb ion implantation. Dry friction tests show that Nb implanted NiTi samples exhibit a lower friction coefficient, narrower wear tracks, fewer wear debris generated, 46 %–62 % reduction in wear width, and29 %–49 % reduction in wear depth compared with the untreated NiTi. Wear resistance is related to the incident parameters, and the Nb implanted NiTi with the incident dose of 2.5 9 1017ionsácm-2, and incident current of2 mA behaves the best wear performance. The lubricating of Nb2O5, good oxidation resistance of Nb in NiTi, and increased micro-hardness of NiTi are responsible for the enhanced wear resistance.

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