International Journal of Hydrogen Energy, Vol.44, No.31, 16877-16886, 2019
Deformation mechanism of capsule-type hydrogen-storage-alloy actuator
A capsule-type actuator using hydrogen storage alloy (HSA) was fabricated and its response behavior was investigated by experiment and finite element analysis. The capsule-type HSA actuator consists of an HSA foil placed on the inner wall of a capsule. In this paper, the displacement change of the actuator made of palladium foil and epoxy resin was experimentally measured in hydrogen atmosphere. As a result, it displaced with the decrease in the capsule height when hydrogen gas was charged, and vice versa. Displacement amount and response time of the actuator depended on the hydrogen pressure during the pressurization, while the response time was independent of the pressure during the evacuation. Also, the HSA actuator's deformation with hydrogen diffusion was simulated using the finite element method. It revealed that hydrogen content in the HSA foil was decreased by high compressive stress, indicating the hydrogen atom was absorbed as a solid solution phase in the HSA foil even when a surrounding hydrogen pressure was higher than the phase transition pressure. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.