SGER: Magnetic Shape Memory Behavior in New Materials

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

Magnetic Shape Memory Behavior in New Materials The proposed work represents a high priority in understanding the magneto-mechanical response of a very promising ferromagnetic shape memory alloy system. The focus is on CoNiAl alloys that undergo shape change associated with applied magnetic fields. Ferromagnetic shape memory alloys undergo rearrangement of the martensitic variant structure under an applied magnetic field which could produce few percent strains. They have advantages over traditional shape memory alloys because of their faster response time, and the CoNiAl has higher strength compared to other ferromagnetic shape memory materials. The experiments include measurement of magnetization versus applied magnetic field for two specific compositions of CoNiAl alloys, the establishment of easy and hard axis of magnetization with testing of several crystal orientations, and the magnetic field induced strain measurements as a function of applied stress. The mechanical response of the CoNiAl alloys will be also evaluated via temperature cycling under stress and observation of the shape memory behavior. The work will have impact in design of new materials and their modeling, and potential applications in various engineering devices such as actuators. The project will provide an opportunity to train a graduate student as well as undergraduate students in understanding the fundamental concepts in transforming materials, ferromagnetism and shape memory behavior.