Abstract Title
Assessment of Corrosive Pathways in NiMnGa Magnetic Shape Memory Alloy
Additional Funding Sources
This project was made possible through NSF Grant No. 1945650.
Abstract
Under stress of an external magnetic field, magnetic shape memory alloys (MSMA) can achieve a strain of up to ~10 percent. Since the discovery of this effect in the Ni-Mn-Ga system in the mid nineties, it has become a great topic of research interest. This system relies on twin boundary motion in the ferromagnetic martensite phases within the single crystal to cause strain. The possible applications of this MSMA system can be limited by its susceptibility to corrosion. This project is an attempt to understand the pathways of corrosion within this Ni-Mn-Ga system. A single sample was tested three times in a three electrode cell with different exposed surfaces. These corrosion tests degraded the surface of the sample with both pitting and crevice corrosion present. The pits formed within the center of the exposed surface with a square box like shape. Crevice corrosion was present on the exterior of the exposed surface which yielded massive degradation of the sample.
Assessment of Corrosive Pathways in NiMnGa Magnetic Shape Memory Alloy
Under stress of an external magnetic field, magnetic shape memory alloys (MSMA) can achieve a strain of up to ~10 percent. Since the discovery of this effect in the Ni-Mn-Ga system in the mid nineties, it has become a great topic of research interest. This system relies on twin boundary motion in the ferromagnetic martensite phases within the single crystal to cause strain. The possible applications of this MSMA system can be limited by its susceptibility to corrosion. This project is an attempt to understand the pathways of corrosion within this Ni-Mn-Ga system. A single sample was tested three times in a three electrode cell with different exposed surfaces. These corrosion tests degraded the surface of the sample with both pitting and crevice corrosion present. The pits formed within the center of the exposed surface with a square box like shape. Crevice corrosion was present on the exterior of the exposed surface which yielded massive degradation of the sample.