High Temperature Magnetic Shape Memory Ni-Mn-Ga Alloys for a New Class of Actuators and Sensor

摘要

This report results from a contract tasking Institute for Metal Physics as follows: This project will conduct a fundamental study of Ni-Mn-Ga-X alloys exhibiting large and stable values of magnetic-field-induced strain at temperatures above 320 K. The objective is to establish the factors determining the values and stability of magnetic shape memory behavior in order to feed the design of a new class of magnetic shape memory actuators and sensors. Specifics of the project are: (i) the complex theoretical and experimental study of a correlation between electronic, magnetic, and crystalline structure and the phase transformation temperatures with occurrence of magnetic shape memory effect (MSME) using various experimental techniques and theoretical calculations in an attempt to determine the physical grounds for design of MSME alloys; (ii) a study of phase, thermal, and mechanical stability of martensite and the corresponding magnetic-field-induced strain in studied Ni-Mn-Ga and Ni- Mn-Ga-X high temperature magnetic shape memory alloys.