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S&M2305 Research Paper of Special Issue https://doi.org/10.18494/SAM.2020.2893 Published in advance: July 31, 2020 Published: August 31, 2020 Enhancement of Fatigue Properties in Sensor Element by Surface Modification [PDF] Kohei Takeda (Received March 31, 2020; Accepted July 14, 2020) Keywords: sensor element, shape memory alloy, superelasticity, ultrasonic shot peening, fatigue
The fatigue property of TiNi shape memory alloy (SMA) is one of the important issues for its use as a sensor element. In this study, the fatigue life of TiNi SMA was improved by ultrasonic shot peening (USP), which can provide the same or a better effect than general shot peening. The effects of the residual stress, surface roughness, and fatigue crack initiation position on the fatigue life of TiNi SMA wires treated by USP were investigated. The results obtained are summarized as follows. (1) The value of the upper stress plateau under the loading process is increased by USP. The increase in stress is almost proportional to the coverage. (2) In the rotating-bending fatigue test, the fatigue life is improved by USP with coverages of 200, 1000, and 2000%. (3) The higher the coverage, the higher the percentage of fatigue cracks that appear from the specimen surface in USP specimens.
Corresponding author: Kohei TakedaThis work is licensed under a Creative Commons Attribution 4.0 International License. Cite this article Kohei Takeda, Enhancement of Fatigue Properties in Sensor Element by Surface Modification, Sens. Mater., Vol. 32, No. 8, 2020, p. 2851-2858. |