Stabilizing a Fine Twin Structure in Ni-Mn-Ga Samples by Coatings and Ion Implantation

K. Ullakko; M. Chmielus; P. Müllner

doi:10.1016/j.scriptamat.2014.09.013

Stabilizing a Fine Twin Structure in Ni-Mn-Ga Samples by Coatings and Ion Implantation

K. Ullakko
, M. Chmielus
, P. Müllner

Micron School of Materials Science and Engineering

Lappeenranta-Lahti University of Technology
University of Pittsburgh

Research output: Contribution to journal › Article › peer-review

13 Scopus citations

Abstract

The surfaces of Ni–Mn–Ga samples were coated with hard TiN and soft elastomer and implanted Nb ⁺ ions. All of these treatments stabilized a dense twin structure. After removing the treated surface layers, the original coarse twin structure reappeared. Compression tests of the ion-implanted sample with fine twins exhibited a continuously increasing, smooth stress–strain curve. Without the surface layer, the stress–strain curve was more rugged and flat, the twinning stress decreased, and one twin boundary moved throughout the entire sample.

Original language	American English
Pages (from-to)	40-43
Number of pages	4
Journal	Scripta Materialia
Volume	94
DOIs	https://doi.org/10.1016/j.scriptamat.2014.09.013
State	Published - 1 Jan 2015

Keywords

Ferromagnetic shape memory
Ion implantation
Surface modifications
Twin stabilization
Twinning

EGS Disciplines

Materials Science and Engineering

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10.1016/j.scriptamat.2014.09.013

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title = "Stabilizing a Fine Twin Structure in Ni-Mn-Ga Samples by Coatings and Ion Implantation",

abstract = " The surfaces of Ni–Mn–Ga samples were coated with hard TiN and soft elastomer and implanted Nb + ions. All of these treatments stabilized a dense twin structure. After removing the treated surface layers, the original coarse twin structure reappeared. Compression tests of the ion-implanted sample with fine twins exhibited a continuously increasing, smooth stress–strain curve. Without the surface layer, the stress–strain curve was more rugged and flat, the twinning stress decreased, and one twin boundary moved throughout the entire sample.",

keywords = "Ferromagnetic shape memory, Ion implantation, Surface modifications, Twin stabilization, Twinning",

author = "K. Ullakko and M. Chmielus and P. M{\"u}llner",

note = "Publisher Copyright: {\textcopyright} 2014 Acta Materialia Inc.",

year = "2015",

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doi = "10.1016/j.scriptamat.2014.09.013",

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T1 - Stabilizing a Fine Twin Structure in Ni-Mn-Ga Samples by Coatings and Ion Implantation

AU - Ullakko, K.

AU - Chmielus, M.

AU - Müllner, P.

PY - 2015/1/1

Y1 - 2015/1/1

N2 - The surfaces of Ni–Mn–Ga samples were coated with hard TiN and soft elastomer and implanted Nb + ions. All of these treatments stabilized a dense twin structure. After removing the treated surface layers, the original coarse twin structure reappeared. Compression tests of the ion-implanted sample with fine twins exhibited a continuously increasing, smooth stress–strain curve. Without the surface layer, the stress–strain curve was more rugged and flat, the twinning stress decreased, and one twin boundary moved throughout the entire sample.

AB - The surfaces of Ni–Mn–Ga samples were coated with hard TiN and soft elastomer and implanted Nb + ions. All of these treatments stabilized a dense twin structure. After removing the treated surface layers, the original coarse twin structure reappeared. Compression tests of the ion-implanted sample with fine twins exhibited a continuously increasing, smooth stress–strain curve. Without the surface layer, the stress–strain curve was more rugged and flat, the twinning stress decreased, and one twin boundary moved throughout the entire sample.

KW - Ferromagnetic shape memory

KW - Ion implantation

KW - Surface modifications

KW - Twin stabilization

KW - Twinning

UR - https://www.scopus.com/pages/publications/84908434467

UR - https://scholarworks.boisestate.edu/mse_facpubs/204

U2 - 10.1016/j.scriptamat.2014.09.013

DO - 10.1016/j.scriptamat.2014.09.013

M3 - Article

SN - 1359-6462

VL - 94

SP - 40

EP - 43

JO - Scripta Materialia

JF - Scripta Materialia

ER -

Stabilizing a Fine Twin Structure in Ni-Mn-Ga Samples by Coatings and Ion Implantation

Abstract

Keywords

EGS Disciplines

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