Public Reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comment regarding this burden estimates or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and
43794.4-MS
SUPPLEMENTARY NOTESThe views, opinions and/or findings contained in this report are those of the author(s) and should not be construed as an official Department of the Army position, policy or decision, unless so designated by other documentation. The specific aims of the project are: 1) Understand governing mechanisms and important physical, mechanical and magnetic parameters responsible for magnetic shape memory phenomena in MSMA alloys in single crystalline form, 2) to develop new nickel, iron or cobalt base ferromagnetic alloy compositions to increase attainable actuation stress levels and to reveal new mageto-thermomechanical mechanisms, 3) to conduct experiments to evaluate whether these compositions will result in good magnetic shape memory response and high actuation force, and 4) to develop a thermodynamically sound model that will predict the coupled effects of mechanical load, magnetic field and temperature on magnetic shape memory behavior. The main accomplishments in the project are: 1) the maximum actuation stress level was increased from 2 MPa to 5 MPa for the magnetic field induced martensite reorientation mechanism for the same amount of actuation strain (6%). 2) For the first time, the team observed cyclic magnetic field induced martensite to austenite transformation. This was confirmed using in-situ magnetic field experiments in an XRD at Argonne National Lab. 3) By utilizing this new actuation mechanism, the team was able to increase the cyclic actuation stress to 24 MPa with about 0.5% actuation strain. These numbers can be increased further. The mechanism has also resulted in field-induced one-way shape memory effect. In this effect, the actuation stress varied between 60 to 100 MPa with actuation strain levels are up to 3%. 4) The team found out the conditions to obtain magnetoelasticity utilizing the above two microstructural mechanisms under cycling loading (cyclic stress under magnetic field or magnetic field under constant stress). 5) development of a thermodynamically consistent phenomenological model which captures the ferromagnetic shape memory effect, i.e. the large macroscopically observable shape change of magnetic shape memory materials under the application of external magnetic fields and magnetizatiob evolution. The significance of these accomplishments is that the selected compositions after specific thermomechanical treatments are revealed promising new actuation mechanism an...