In-situ nanoindentation study of phase transformation in magnetic shape memory alloys

April 18, 2014 by Hemali Tanna

Texas A&M University researchers led by Dr. Xinghang Zhang in the Department of Mechanical Engineering have examined stress induced martensitic phase transformations in magnetic shape memory alloys via in-situ nanoindentation technique.

The paper titled "Two Types of Martensitic Phase Transformations in Magnetic Shape Memory Alloys by in-situ Nanoindentation Studies" was published in the March 31 issue (2014) of Advanced Materials. The first author of the paper is Mr. Yue Liu, a Ph.D. candidate in Dr. Zhang's research group.

Ni based magnetic alloys (MSMAs) have broad applications for actuators and microelectromechanical systems (MEMS) devices. Two-stage stress induced martensitic phase transformation, a widely observed phenomenon in these alloys, is described conventionally as a first stage L21 (austenite)-to-10M/14M (M: modulated martensite) transition, followed by a second stage 14M-to-L10 (tetragonal martensite) transformation at higher stresses.

During their in-situ nanoindentation experiments on Ni54Fe19Ga27 in a transmission electron microscope, Zhang and his graduate student, Mr. Yue Liu, discovered two distinctive types of martensitic phase transformation: A reversible gradual L21-to-10M/14M phase transformation at low stress, and an irreversible abrupt transition from residual L21-to-L10 martensite at higher stress. This study provides new perspectives on understanding stress induced in MSMAs.

Explore further: New materials turn heat into electricity

More information: Liu, Y., Karaman, I., Wang, H. and Zhang, X. (2014), "Two Types of Martensitic Phase Transformations in Magnetic Shape Memory Alloys by In-Situ Nanoindentation Studies." Adv. Mater.. DOI: 10.1002/adma.201400217

Related Stories

New materials turn heat into electricity

November 7, 2011

Most of today's power plants--from some of the largest solar arrays to nuclear energy facilities--rely on the boiling and condensing of water to produce energy.

Can metals remember their shape at nanoscale, too?

November 8, 2011

University of Constance physicists Daniel Mutter and Peter Nielaba have visualized changes in shape memory materials down to the nanometric scale in an article about to be published in the European Physical Journal B.

Advances in glass alloys lead to strength, flexibility

March 4, 2014

(Phys.org) —What do some high-end golf clubs and your living room window have in common? The answer is glass, but in the golf clubs' case it's a specialized glass product, called metallic glass, with the ability to be bent ...

Recommended for you

Nano-watermark sorts fakes from genuines

June 27, 2016

Nanoga, an EPFL-based startup, has developed a technique to put a nanoscopic watermark onto glass or ceramic. Products with this watermark, which is invisible to the naked eye and only shows up under ultraviolet light, are ...

Hybrid nanogenerator harvests hard-to-reach ocean energy

June 21, 2016

(Phys.org)—Energy from the ocean, or "blue energy," is arguably the most underexploited power source, according to researchers in a new study. Although the oceans contain enough energy to meet all of the world's energy ...

Nanoscientists develop the 'ultimate discovery tool'

June 23, 2016

The discovery power of the gene chip is coming to nanotechnology. A Northwestern University research team is developing a tool to rapidly test millions and perhaps even billions or more different nanoparticles at one time ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.