| Binary Fe-Pd alloy is a new magnetically controlled shape memoryalloy (MSMA) with a second-order fcc-fct phase transformation andsuperelasticity. Therefore, Fe-Pd alloy has an extremely broad applicationprospect. However, the mechanisms of martensitic transformation andshape memory effect in Fe-Pd alloy are still inconclusive.Introducing coordinating agent to electrolyte can help shortening thereduction potential gap between Pd2+and Fe2+and making a stablePd2+-Fe2+solution, which makes the co-deposition of these two elementspossible. A series of Fe-Pd films with different components wereprepared via pulse electrodeposition. The components of Fe-Pd film canbe mainly influenced by current density, electrolyte concentration, andcharacteristic of cathode surface. Meanwhile, the surface morphology ofthe Fe-Pd film is greatly influenced by not only the cathode surface, butalso the thickness of the film, as a result of the hydrogen absorption properties of palladium, which can make the electrodeposition uneven.XRD spectrums indicate that the as-deposited Fe-24at%Pd film oncopper cathode contains mainly an fcc phase, and maintains the fcc phaseafter annealing and quenching into LIN. The lattice parameter decreasesafter annealing, which may be caused by the hydrogen absorption ofpalladium in the alloy and the diffusion of Cu on the substrate. Combinedwith DSC and PPMS analysis, no regular fcc-bcc phase transformationcould be found upon cooling. The stability of the high-temperature fccphase is ascribed to the nano-scale grains in the pulse electrodepositedFe-Pd film. |
