Faculty Advisor: Prof. Peter Müllner
Magnetic shape-memory alloys have the ability to deform — stretch and strain, similar to the mechanics of muscles — when exposed to a variable magnetic field. Conversely, when deformed the material magnetizes and induces a voltage in a coil wound around it; thus, magnetic shape-memory alloys provide technology for micro-energy harvesting. This new paradigm in engineering opens the door for building mechanical devices at the nanoscale; however, the fatigue properties of magnetic-shape memory alloys limit their lifetimes. Recent research has shown that the fatigue behavior of magnetic shape memory alloys depends strongly on surface finish. In particular, we have developed a micropeening process that increases the fatigue life by more than three orders of magnitude. The goal of this project is to understand the impact of micropeening parameters on near-surface defect structure and magneto-mechanical properties of magnetic shape memory alloys.
Role of Participant(s):
Students will learn to cast an alloy from raw materials, anneal it, prepare samples for optical microscopy, and finally grow a single crystal. They will then perform a systematic study on monocrystalline magnetic shape memory properties by treating the sample surface with the micropeening process. The students will vary process parameters such as peening pressure and time and then characterize the samples with respect to their defect structure and magneto-mechanical properties. They will work closely with a graduate student and learn to operate characterization instruments such as a vibrating sample magnetometer and a mechanical testing system.