X-Ray Diffraction Studies on Ti-Pd Shape Memory Alloys

2014 ◽  
Vol 783-786 ◽  
pp. 2517-2522
Author(s):  
Raju Arockiakumar ◽  
Madoka Takahashi ◽  
Satoshi Takahashi ◽  
Yoko Yamabe-Mitarai
Keyword(s):  
Phase Transformation ◽  
Shape Memory ◽  
Low Temperatures ◽  
Periodic Table ◽  
Room Temperature ◽  
Group Iv ◽  
X Ray Diffraction ◽  
Transformation Behavior ◽  
X Ray ◽  
B2 Phase

The phase transformation behavior of Ti-50Pd-5x (x =Zr, Hf, V, Nb, Ta, Cr, Mo, W) (at.%) alloys was studied by X-ray diffraction measurements from room temperature to 800 oC. In all the alloys, B19 martensite was observed at room temperature and it transformed to B2 phase upon heating. In addition, peaks corresponding to formation of (Ti, x)2Pd3 phase was seen for all the alloys. However, the temperature of formation of (Ti, x)2Pd3, interestingly, varied with respect to the elements group from the periodic table. Elements except from group IV (Zr and Hf) have been identified to accelerate the formation of (Ti, x)2Pd3 phase even at low temperatures (~400 oC).

Magnetic Properties of Sputtered Fe-O and Co-O Thin Films

1995 ◽  
Vol 403 ◽  
Author(s):  
D. V. Dimitrov ◽  
A. S. Murthy ◽  
G. C. Hadjipanayis ◽  
C. P. SWANN
Keyword(s):  
Grain Size ◽  
Low Temperatures ◽  
Room Temperature ◽  
Oxide Films ◽  
X Ray Diffraction ◽  
Dc Magnetron Sputtering ◽  
Large Shift ◽  
X Ray ◽  
Grain Size And Shape ◽  
Spherical Grains

AbstractFe-O and Co-O films were prepared by DC magnetron sputtering in a mixture of Ar and O2 gases. By varying the oxygen to argon ratio, oxide films with stoichiometry FeO, Fe3O4, α-Fe2O3, CoO and Co3O4 were produced. TEM studies showed that the Fe – oxide films were polycrystalline consisting of small almost spherical grains, about 10 nm in size. Co-O films had different microstructure with grain size and shape dependent on the amount of oxygen. X-ray diffraction studies showed that the grains in Fe-O films were randomly oriented in contrast to Co-O films in which a <111> texture was observed. Pure FeO and α-Fe2O3 films were found to be superparamagnetic at room temperature but strongly ferromagnetic at low temperatures in contrast to the antiferromagnetic nature of bulk samples. A very large shift in the hysteresis loop, about 3800 Oe, was observed in field cooled Co-CoO films indicating the presence of a large unidirectional exchange anisotropy.

scholarly journals Nanocrystal, phase transformation and microstructure of Ni50Ti50 shape memory alloy

2018 ◽  
Vol 24 (02) ◽  
pp. 22-25
Author(s):  
Dovchinvanchig M ◽  
Chunwang Zhao
Keyword(s):  
Differential Scanning Calorimetry ◽  
Phase Transformation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
One Step ◽  
Niti Matrix ◽  
Electronic Microscope

The nanocrystal, phase transformation and microstructure behavior of Ni50Ti50 shape memory alloy was investigated by scanning electronic microscope, X-ray diffraction and differential scanning calorimetry. The results showed that the microstructure of Ni-Ti binary alloy consists of the NiTi2 phase and the NiTi matrix phase. One-step phase transformation was observed alloy.

scholarly journals An operando X-ray diffraction study of chloroaluminate anion-graphite intercalation in aluminum batteries

2018 ◽  
Vol 115 (22) ◽  
pp. 5670-5675 ◽  
Author(s):  
Chun-Jern Pan ◽  
Chunze Yuan ◽  
Guanzhou Zhu ◽  
Qian Zhang ◽  
Chen-Jui Huang ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Room Temperature ◽  
Negative Electrode ◽  
Discharge Voltage ◽  
Battery Life ◽  
X Ray Diffraction ◽  
X Ray ◽  
Stage 4 ◽  
Graphite Intercalation ◽  
Battery Discharge

We investigated rechargeable aluminum (Al) batteries composed of an Al negative electrode, a graphite positive electrode, and an ionic liquid (IL) electrolyte at temperatures down to −40 °C. The reversible battery discharge capacity at low temperatures could be superior to that at room temperature. In situ/operando electrochemical and synchrotron X-ray diffraction experiments combined with theoretical modeling revealed stable AlCl4−/graphite intercalation up to stage 3 at low temperatures, whereas intercalation was reversible up to stage 4 at room temperature (RT). The higher-degree anion/graphite intercalation at low temperatures affords rechargeable Al battery with higher discharge voltage (up to 2.5 V, a record for Al battery) and energy density. A remarkable cycle life of >20,000 cycles at a rate of 6C (10 minutes charge time) was achievable for Al battery operating at low temperatures, corresponding to a >50-year battery life if charged/discharged once daily.

Phase Transformation Behavior and Stability of LiNiO 2 Cathode Material for Li‐Ion Batteries Obtained from In Situ Gas Analysis and Operando X‐Ray Diffraction

ChemSusChem ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 2240-2250 ◽  
Author(s):  
Lea de Biasi ◽  
Alexander Schiele ◽  
Maria Roca‐Ayats ◽  
Grecia Garcia ◽  
Torsten Brezesinski ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Cathode Material ◽  
Gas Analysis ◽  
Li Ion Batteries ◽  
X Ray Diffraction ◽  
Transformation Behavior ◽  
X Ray ◽  
Phase Transformation Behavior ◽  
Li Ion

Structural Characterization of Co70-xNixGa30 Ferromagnetic Shape Memory Alloys

2008 ◽  
Vol 52 ◽  
pp. 103-108 ◽  
Author(s):  
Sidananda Sarma ◽  
A. Srinivasan
Keyword(s):  
Magnetic Susceptibility ◽  
Shape Memory ◽  
Room Temperature ◽  
Structural Parameters ◽  
Ac Magnetic Susceptibility ◽  
X Ray Diffraction ◽  
Ferromagnetic Shape Memory Alloys ◽  
Two Phase ◽  
X Ray ◽  
Ferromagnetic Shape Memory

Polycrystalline ingots of Co70–xNixGa30 (20 ≤ x ≤ 26) ferromagnetic shape memory alloy (FSMA) were prepared by arc melting elemental powders followed by homogenization at 1230 °C for 24 hrs and quenching in liquid nitrogen. Room temperature X-Ray diffraction (XRD) patterns of as-quenched samples exhibited single-phase tetragonal structure for alloy compositions with x = 21 to 26, and a two-phase structure (cubic A2-phase along with weak tetragonal phase) for the alloy with x = 20. Rietveld refinement was performed on the X-ray diffraction patterns to obtain the refined structural parameters. Differential Scanning Calorimeter (DSC) curves recorded from 30 °C to 250 °C revealed martensite-austenite and austenite-martensite transformations in all alloys except the alloy with composition x = 20. Low temperature ac magnetic susceptibility measurements confirmed the existence of martensitic transformations in the alloy with x = 20. The structural transformation temperatures show a linear variation with e/a ratio. All the alloys were ferromagnetic at room temperature. Curie temperature was determined using a high temperature ac magnetic susceptibility measurement set-up.

Transformation Behavior and Shape Memory Characteristics of Ti-45Ni-5Cu(at%) Alloy Ribbons Fabricated by Melt Spinning

2004 ◽  
Vol 449-452 ◽  
pp. 1093-1096 ◽  
Author(s):  
Tae Hyun Nam ◽  
Jae Hwa Lee ◽  
Tae Yeon Kim ◽  
Yeon Wook Kim
Keyword(s):  
Shape Memory ◽  
Melt Spinning ◽  
Constant Load ◽  
X Ray Diffraction ◽  
Transformation Behavior ◽  
X Ray ◽  
Density Of Dislocations ◽  
Large Lattice ◽  
One Step ◽  
Memory Characteristics

Transformation behaviors and shape memory characteristics of Ti-45Ni-5Cu alloy ribbons fabricated by melt spinning were investigated by means of optical microscopy, differential scanning calorimetries(DSC), X-ray diffraction and thermal cycling tests under constant load. They depended largely on temperatures of liquid metal. The B2-B19-B19’ two-step transformation occurred in the ribbons fabricated with the liquid whose temperature was higher than 1723 K, while the B2-B19’ one-step transformation occurred in the ribbons with the liquid at 1673 K. The stabilization of the B19 martensite in Ti-45Ni-5Cu alloy ribbons was ascribed to the high density of dislocations which made strong resistance to large lattice deformation associated with a formation of the B19’ martensite.

High-energy synchrotron X-ray diffraction measurements of simple bending of pseudoelastic NiTi shape memory alloy wires

2016 ◽  
Vol 31 (2) ◽  
pp. 104-109 ◽  
Author(s):  
Baozhuo Zhang ◽  
Marcus L. Young
Keyword(s):  
Phase Transformation ◽  
Shape Memory ◽  
High Energy ◽  
Bend Angle ◽  
Niti Shape Memory Alloy ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Mechanical Bending ◽  
Xrd Patterns

Many technological applications of austenitic shape memory alloys (SMAs) involve cyclical mechanical loading and unloading in order to take advantage of pseudoelasticity. In this paper, we investigated the effect of mechanical bending of pseudoelastic NiTi SMA wires using high-energy synchrotron radiation X-ray diffraction (SR-XRD). Differential scanning calorimetry was performed to identify the phase transformation temperatures. Scanning electron microscopy images show that micro-cracks in compressive regions of the wire propagate with increasing bend angle, while tensile regions tend not to exhibit crack propagation. SR-XRD patterns were analyzed to study the phase transformation and investigate micromechanical properties. By observing the various diffraction peaks such as the austenite (200) and the martensite (${\bar 1}12$), (${\bar 1}03$), (${\bar 1}11$), and (101) planes, intensities and residual strain values exhibit strong anisotropy, depending upon whether the sample is in compression or tension during bending.

Phase Transformation in Ti-Ni-Ta Shape Memory Alloy

2007 ◽  
Vol 130 ◽  
pp. 147-150 ◽  
Author(s):  
Zdzisław Lekston ◽  
Tomasz Goryczka
Keyword(s):  
Phase Transformation ◽  
Martensitic Transformation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Medical Application ◽  
Precipitation Process ◽  
X Ray Diffraction ◽  
Martensitic Transformation Temperature ◽  
X Ray ◽  
Solution Treated

A new Ti50Ni48.7Ta1.3 shape memory alloy was designed for medical application. In order to influence the martensitic transformation temperature the alloy was solution treated and additionally aged at 400oC for various time. Phase transformation was studied applying differential scanning calorimeter (DSC) and X-ray diffraction techniques. The ageing causes that the martensitic transformation occurs in two steps: B2↔R↔B19’ during cooling and heating. During cooling the transformations: B2→R and R→B19’ are well separated whereas on heating they are overlapped. Also ageing causes a shift of temperatures of the martensitic transformation into the higher region. It is due to the precipitation process. Precipitates of the Ni4Ti3 phase were observed. Applied thermal treatment leads to shift of the transformation temperatures below temperature of a human body. This makes the Ti-Ni-Ta alloy attractive for application in medicine.

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