Structure and Phase Transformation in Ni-Co-Mn-In Ferromagnetic Shape Memory Alloys

2013 ◽  
Vol 203-204 ◽  
pp. 240-245
Author(s):  
Katarzyna Reclik ◽  
Krystian Prusik ◽  
Tomasz Goryczka ◽  
Marian Kubisztal ◽  
Danuta Stróż
Keyword(s):  
Phase Transformation ◽  
Martensitic Transformation ◽  
Room Temperature ◽  
Parent Phase ◽  
Indium Content ◽  
Gamma Phase ◽  
Ferromagnetic Shape Memory Alloys ◽  
Columnar Grains ◽  
One Step ◽  
Ferromagnetic Shape Memory

In the present study the series of the Ni46.2Co5.0Mn36.1In12.6, Ni48.7Co5.2Mn34.4In11.6 and Ni45.6Co4.8Mn36.4In13.2 alloys (at. %) were studied. The influence of the indium addition on structure and phase transitions was studied. All alloys were annealed at 900°C for 24 hours and then slowly cooled in the furnace. After annealing all of the studied alloys showed the macrostructure of radially oriented columnar grains, which lied in the direction perpendicular to the casting axis. For the alloy containing about 13 at. % of indium the monoclinic 14M modulated martensite was stated at room temperature. Apart from the modulated martensite in a1_133 alloy the gamma phase was also observed. For alloy with higher indium content the mixture of cubic L21 parent phase and cubic gamma phase was identified. All studied alloys showed one-step martensitic transformation.

TEM Study of Ni-Mn-Co-In Ferromagnetic Shape Memory Alloys

2012 ◽  
Vol 186 ◽  
pp. 271-274
Author(s):  
Krystian Prusik ◽  
Katarzyna Bałdys ◽  
Danuta Stróż
Keyword(s):  
Martensitic Transformation ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Smart Materials ◽  
Parent Phase ◽  
Cobalt Content ◽  
Indium Content ◽  
Ferromagnetic Shape Memory Alloys ◽  
Transformation Temperatures ◽  
Ferromagnetic Shape Memory

Ferromagnetic shape memory alloys (FSMA) are relatively new smart materials group. Recently, new FSMA from NiMnX (X=Sb, Sn, In, Co+In) systems are considered as alternative to the well known NiMnGa alloys. Four alloys of the following compositions: Ni43Mn35Co4In18, Ni41Mn35Co4In20, Ni42Mn35Co5In18, Ni40Mn35Co5In20 were studied in order to determine microstructure, phase composition and martensitic transformation temperatures versus their chemical composition. Structure of the alloys was studied by optical and transmission electron microscopy (TEM). All of the studied alloys showed macrostructure consisting of radially oriented columnar grains in the direction perpendicular to the casting axis. The structure of the phases occurred in the studied alloys depended on the cobalt and indium content. For the alloys containing 20 at. % of In at room temperature only L21 parent phase was observed whereas for those containing 18 at. % of In either single phase 14M modulated martensite or mixture of 14M martensite and L21 parent phase were seen. DSC measurements showed in studied alloys single-state martensitic transformation. Decrease In content of 2 at.% caused about 80°C fall of martensitic transformation temperatures. Curie temperature Tc increases of 20°C with 1 at% rise of the cobalt content.

Phase Transformation and Microstructures in Ni and Cu Base Ferromagnetic Shape Memory Alloys

2007 ◽  
Vol 539-543 ◽  
pp. 3157-3162 ◽  
Author(s):  
Takuro Kushima ◽  
Koichi Tsuchiya ◽  
Yasuyoshi Sho ◽  
Takafumi Yamada ◽  
Yoshikazu Todaka ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Magnetic Property ◽  
Chemical Composition ◽  
Martensitic Transformation ◽  
Curie Temperature ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Ferromagnetic Shape Memory Alloys ◽  
Ferromagnetic Shape Memory

Effect of chemical composition was investigated on martensitic transformation temperatures, Curie temperature, magnetization and microstructures for Ni-(Mn, Fe, Co)-Ga and Cu-Mn-Ga systems. In the Ni-(Mn, Fe, Co)-Ga alloys, which is a modification of Ni-Mn-Ga systems, the Af and TC over 400 K were achieved. Cu-Mn-Ga alloy exhibited shape memory effect at temperatures above 373 K and had TC over 400 K. Furthermore, Cu-Mn-Ga exhibits good ductility even in polycrystalline condition unlike the case of Ni-Mn-Ga. Effect of addition of the fourth element to improve the magnetic property is under investigation.

Isothermal Martensitic Transformation Kinetics in Ni-Mn-Sn Ferromagnetic Shape Memory Alloys

2009 ◽  
Vol 1200 ◽  
Author(s):  
Patrick Shamberger ◽  
Alexandre Pakhomov ◽  
Fumio Ohuchi
Keyword(s):  
Phase Transformation ◽  
Martensitic Transformation ◽  
Martensite Transformation ◽  
Transformation Kinetics ◽  
Transformation Behavior ◽  
Ferromagnetic Shape Memory Alloys ◽  
Austenite Transformation ◽  
Ferromagnetic Shape Memory ◽  
Kinetics Of ◽  
Isothermal Martensitic Transformation

AbstractThis study examines the kinetics of the martensitic phase transformation in a representative Ni-Mn-Sn Heusler alloy. Here, we present data on isothermal and continuous cooling/warming transformations in both bulk polycrystalline and individual small particle samples. We demonstrate that while the martensite to austenite transformation proceeds very rapidly (faster than the time-scale of our observations), the austenite to martensite transformation has a significant isothermal component. A similar asymmetry is also noted in transformation behavior of individual martensite plates. We conclude that the observed time dependence is due primarily to nucleation-limited kinetics.

Martensitic Transformation, Structure and Magnetic Properties of Co-Ni-Ga Ferromagnetic Shape Memory Alloys

2007 ◽  
Vol 130 ◽  
pp. 141-146 ◽  
Author(s):  
B. Kostrubiec ◽  
Krystian Prusik ◽  
Ł. Madej ◽  
Henryk Morawiec
Keyword(s):  
Magnetic Properties ◽  
Martensitic Transformation ◽  
Structural Changes ◽  
Parent Phase ◽  
Martensite Phase ◽  
Ferromagnetic Shape Memory Alloys ◽  
Two Phase ◽  
Polycrystalline Alloys ◽  
Transformation Structure ◽  
Ferromagnetic Shape Memory

In the present paper the effect of heat treatment on microstructure, martensitic transformation temperatures and magnetic properties behavior of Co-Ni-Ga pollycrystal was discussed in detail. Microscopic observations revealed two types of two phase polycrystalline alloys: i) martensite with γ-precipitates and ii) parent phase with γ-precipitates. Making use of Xray and electron diffraction methods the crystal structure of martensite phase was identified as bct structure (with co/ao about 1.2). Annealing of Co-Ni-Ga alloy at 1223K/40 min causes a separation of martensitic and magnetic transformation and an increase of the Curie temperature by about 70K, after this annealing any significant structural changes in the parent (martensitic) and γ phase are not observed.

scholarly journals Tunable Martensitic Transformation and Magnetic Properties of Sm-Doped NiMnSn Ferromagnetic Shape Memory Alloys

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1115
Author(s):  
Najam ul Hassan ◽  
Mohsan Jelani ◽  
Ishfaq Ahmad Shah ◽  
Khalil Ur Rehman ◽  
Abdul Qayyum Khan ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Martensitic Transformation ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Transformation Temperature ◽  
Room Temperature ◽  
Field Variation ◽  
Martensitic Transformation Temperature ◽  
Ferromagnetic Shape Memory Alloys ◽  
Ferromagnetic Shape Memory

NiMnSn ferromagnetic shape memory alloys exhibit martensitic transformation at low temperatures, restricting their applications. Therefore, this is a key factor in improving the martensitic transformation temperature, which is effectively carried out by proper element doping. In this research, we investigated the martensitic transformation and magnetic properties of Ni43Mn46-x SmxSn11 (x = 0, 1, 2, 3) alloys on the basis of structural and magnetic measurements. X-ray diffraction showed that the crystal structure transforms from the cubic L21 to the orthorhombic martensite and gamma (γ) phases. The reverse martensitic and martensitic transformations were indicated by exothermic and endothermic peaks in differential scanning calorimetry. The martensitic transformation temperature increased considerably with Sm doping and exceeded room temperature for Sm = 3 at. %. The Ni43Mn45SmSn11 alloy exhibited magnetostructural transformation, leading to a large magnetocaloric effect near room temperature. The existence of thermal hysteresis and the metamagnetic behavior of Ni43Mn45SmSn11 confirm the first-order magnetostructural transition. The magnetic entropy change reached 20 J·kg−1·K−1 at 266 K, and the refrigeration capacity reached ~162 J·Kg−1, for Ni43Mn45SmSn11 under a magnetic field variation of 0–5 T.

TEM Studies on the Microstructure in Ferromagnetic Shape Memory Alloys

2008 ◽  
Vol 47-50 ◽  
pp. 515-518
Author(s):  
Y. Murakami ◽  
T. Yano ◽  
Daisuke Shindo
Keyword(s):  
Martensitic Transformation ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Parent Phase ◽  
Magnetic Domain ◽  
High Temperature Phase ◽  
Phase Changes ◽  
Temperature Phase ◽  
Ferromagnetic Shape Memory Alloys ◽  
Ferromagnetic Shape Memory

The magnetic domain structures of the cubic parent phase (high-temperature phase) in ferromagnetic shape memory alloys (SMAs) have been studied by electron holography. In a Ni51Fe22Ga17 alloy, the magnetic flux distribution in the parent phase changes dramatically before the onset of martensitic transformation. In contrast, a Ni45Co5Mn36.7In13.3 alloy—a recently developed ferromagnetic SMA—does not show appreciable changes in the magnetic domain structure upon cooling. The anomaly observed in the Ni51Fe22Ga17 alloy appears to be due to lattice distortions, which become more pronounced as the temperature approaches the martensitic transformation start temperature, Ms.

Microstructural Studies of NiCoMnIn Magnetic Shape Memory Ribbons

2013 ◽  
Vol 738-739 ◽  
pp. 436-440 ◽  
Author(s):  
Krystian Prusik ◽  
Katarzyna Bałdys ◽  
Danuta Stróż ◽  
Tomasz Goryczka ◽  
Józef Lelątko
Keyword(s):  
Melt Spinning ◽  
Room Temperature ◽  
Parent Phase ◽  
Magnetic Shape Memory ◽  
Melt Spun ◽  
Columnar Grains ◽  
Ebsd Technique ◽  
Microstructural Studies ◽  
Melt Spinning Technique ◽  
Scanning Electron

In present paper two ribbons of the Ni44Co6Mn36In14 (at.%) were prepared under different melt-spinning technique conditions. Microstructure of the ribbons was studied by scanning electron microscopy (SEM). Depending on the liquid ejection overpressure two types of ribbons microstructures were observed. Ribbon T1 for which ejection overpressure was 1.5 bar showed typical melt-spun ribbon microstructure consisting of a top layer of small equi-axial grains and columnar grains below. For T2 ribbon (ejection overpressure 0.2 bar) only a small fraction of the columnar grains were observed. Structure analysis of the ribbons performed by XRD showed that at room temperature both ribbons have B2 parent phase superstructure. No gamma phase precipitates were observed. In order to determine the orientation of the grains the EBSD technique was applied.

One-step room temperature rapid synthesis of Cu2Se nanostructures, phase transformation, and formation of p-Cu2Se/p-Cu3Se2heterojunctions

CrystEngComm ◽  
2016 ◽  
Vol 18 (27) ◽  
pp. 5202-5208 ◽  
Author(s):  
Lianjie Zhu ◽  
Yanxing Zhao ◽  
Wenjun Zheng ◽  
Ningning Ba ◽  
Guangzhi Zhang ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Room Temperature ◽  
Rapid Synthesis ◽  
One Step

Structure and Phase Stability of NiMnGa Ferromagnetic Shape Memory Alloys by Experimental and Ab Initio Techniques

2010 ◽  
Vol 638-642 ◽  
pp. 2040-2045 ◽  
Author(s):  
Claude Esling ◽  
Dao Yong Cong ◽  
Jing Bai ◽  
Yu Dong Zhang ◽  
Jean Marc Raulot ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Orientation Relationship ◽  
Room Temperature ◽  
Phenomenological Theory ◽  
Shear Angle ◽  
Martensitic Structure ◽  
Ferromagnetic Shape Memory Alloys ◽  
Austenite Grain ◽  
Ferromagnetic Shape Memory ◽  
Martensitic Variants

This paper summarizes some of our recent results on crystal structure, microstructure, orientation relationship between martensitic variants and crystallographic features of martensitic transformation in Ni-Mn-Ga FSMAs. It was shown that Ni53Mn25Ga22 has a tetragonal I4/mmm martensitic structure at room temperature. The neighboring martensitic variants in Ni53Mn25Ga22 have a compound twinning relationship with the twinning elements K1={112}, K2={11-2}, η1=<11-1>, η2=<111>, P={1-10} and s=0.379. The ratio of the relative amounts of twins within the same initial austenite grain is ~1.70. The main orientation relationship between austenite and martensite is Kurdjumov-Sachs (K-S) relationship. Based on the crystallographic phenomenological theory, the calculated habit plane is {0.690 -0.102 0.716}A (5.95° from {101}A), and the magnitude, direction and shear angle of the macroscopic transformation shear are 0.121, <-0.709 0.105 0.698>A (6.04° from <-101>A) and 6.88°, respectively.

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