Additional Funding Sources
We acknowledge financial support through the National Science Foundation project Grant No. NSF-DMR 1710640. The project described was also supported by the National Science Foundation via the Research Experience for Undergraduates Site: Materials for Society (Award No. 1950305) and by the Micron School of Materials Science & Engineering at Boise State University.
Abstract
Magnetic shape-memory (MSM) materials use magnetic energy to generate large deformation. Nickel-Manganese-Gallium is a prominent MSM crystal that can be strained to 6% of its length. The alloy degrades and breaks after repeated loading, a behavior called fatigue. Bombarding the surface of the material with minuscule glass beads (micropeening) increases the number of loading cycles thousandfold; however, this decreases the maximum strain. In this project, stress and strain were measured before and after micropeening at different pressures to identify a quantitative relationship between process parameters and the dynamic material properties. Preliminary results show that micropeening at 25 psi preserves a large part of the strain while micropeening at 30 psi suppresses most of the strain.
Magneto-Mechanics of Magnetic Shape-Memory Crystals with Micropeened Surfaces
Magnetic shape-memory (MSM) materials use magnetic energy to generate large deformation. Nickel-Manganese-Gallium is a prominent MSM crystal that can be strained to 6% of its length. The alloy degrades and breaks after repeated loading, a behavior called fatigue. Bombarding the surface of the material with minuscule glass beads (micropeening) increases the number of loading cycles thousandfold; however, this decreases the maximum strain. In this project, stress and strain were measured before and after micropeening at different pressures to identify a quantitative relationship between process parameters and the dynamic material properties. Preliminary results show that micropeening at 25 psi preserves a large part of the strain while micropeening at 30 psi suppresses most of the strain.