Plasticity of bulk metallic glasses improved by controlling the solidification condition

2008 ◽  
Vol 23 (4) ◽  
pp. 941-948 ◽  
Author(s):  
Z.W. Zhu ◽  
S.J. Zheng ◽  
H.F. Zhang ◽  
B.Z. Ding ◽  
Z.Q. Hu ◽  
...  
Keyword(s):  
Metallic Glasses ◽  
Bulk Metallic Glasses ◽  
High Energy ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Solidification Condition ◽  
X Ray ◽  
Transmission Electron ◽  
Injection Casting

Different bulk metallic glasses (BMGs) were prepared in ductile Cu47.5Zr47.5Al5, Zr62Cu15.4Ni12.6Al10, and brittle Zr55Ni5Al10Cu30 alloys by controlling solidification conditions. The achieved microstructures were characterized by x-ray diffraction, differential scanning calorimetry, transmission electron microscopy, and synchrotron- based high-energy x-ray diffraction. Monolithic BMGs obtained by high-temperature injection casting are brittle, while BMGs bearing some nanocrystals with the size of 3 to 7 nm and 2 to 4 nm, obtained by low-temperature injection casting and in situ suction casting, respectively, exhibit good plasticity. It indicates that the microstructures of BMGs are closely affected by the solidification conditions. Controlling the solidification conditions could improve the plasticity of BMGs.

Microstructures and Synthesis of Noble Metal-Based Bulk Metallic Glasses (Zr-Be-Ni-Ti)

2016 ◽  
Vol 17 ◽  
pp. 1-6
Author(s):  
M. Abo-Elsoud
Keyword(s):  
Metallic Glasses ◽  
Thermal Analyses ◽  
Bulk Metallic Glasses ◽  
High Energy ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Stage Crystallization ◽  
Energy Ball ◽  
Experimental Findings

High-energy ball-milling in hexane medium was employed to prepare Nobel Zr-based bulk metallic glasses (BMGs) alloy of three different nominal compositions Zr47Be23Ni15Ti15, Zr50Be20Ni15Ti15 and Zr52Be18Ni15Ti15, numbers indicate at.%). The glass forming ability was found to increase with decreasing Zr and increasing Be content, which can be ascribed to the enhanced atomic size mismatch of the constituents on Be addition. Amorphous Zr47Be23Ni15Ti15 powder undergoes two-stage crystallization with onset temperatures at 640 and 700 K and glass transition temperature Tg at 566 K. In contrast, the Zr50Be20Ni15Ti15 and Zr52Be18Ni15Ti15 samples remained crystalline to a certain extent even after prolonged milling and contained FCC Zr crystallites. Structural characterization was done by X-ray diffraction (XRD) and transmission electron microscopy (TEM). In addition, thermal analyses were performed by means of differential scanning calorimetry (DSC) thermogram to justify the experimental findings.

scholarly journals Local strain behavior of bulk metallic glasses under tension studied by in situ x-ray diffraction

2009 ◽  
Vol 94 (1) ◽  
pp. 011911 ◽  
Author(s):  
X. D. Wang ◽  
J. Bednarcik ◽  
H. Franz ◽  
H. B. Lou ◽  
Z. H. He ◽  
...  
Keyword(s):  
Metallic Glasses ◽  
Bulk Metallic Glasses ◽  
Local Strain ◽  
X Ray Diffraction ◽  
X Ray ◽  
Strain Behavior

Investigation of Structure and Properties of the Al–Y–Ni–Co–Cu Metallic Glasses

2002 ◽  
Vol 17 (5) ◽  
pp. 1014-1018 ◽  
Author(s):  
Dmitri V. Louzguine ◽  
Akihisa Inoue
Keyword(s):  
Electron Microscopy ◽  
Metallic Glasses ◽  
Crystallization Behavior ◽  
Supercooled Liquid ◽  
Partial Replacement ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron

The present paper reports the effect of partial replacement of Ni by Cu in the Al85Y8Ni5Co2 alloy. The studied alloys were produced by rapid solidification. Glass-formation, crystallization behavior, and stability of the supercooled liquid were studied by x-ray diffraction, transmission electron microscopy, and differential scanning calorimetry. Partial replacement of Ni by Cu in the Al85Y8Ni5Co2 metallic glass caused formation of the nanoscale α–Al particles and resulted in a decrease in the crystallization temperature and disappearance of the supercooled liquid.

scholarly journals Tensile behavior of bulk metallic glasses by in situ x-ray diffraction

2007 ◽  
Vol 91 (8) ◽  
pp. 081913 ◽  
Author(s):  
X. D. Wang ◽  
J. Bednarcik ◽  
K. Saksl ◽  
H. Franz ◽  
Q. P. Cao ◽  
...  
Keyword(s):  
Metallic Glasses ◽  
Bulk Metallic Glasses ◽  
Tensile Behavior ◽  
X Ray Diffraction ◽  
X Ray

Structural properties of Eu doped GaN and its relation with luminescence properties

2004 ◽  
Vol 831 ◽  
Author(s):  
Hyungjin Bang ◽  
Takahiro Maruyama ◽  
Shigeya Naritsuka ◽  
Katsuhiro Akimoto
Keyword(s):  
Structural Properties ◽  
High Energy ◽  
Concentration Quenching ◽  
High Energy Electron ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Close Relationship ◽  
The Eu

ABSTRACTThe Structural properties of Europium (Eu) doped GaN and its relation with optical properties were studied. Concentration quenching of the intensity of the Eu related luminescence observed when Eu concentration exceeds 3 at.%. In situ reflection high-energy electron diffraction (RHEED), transmission electron microscopy (TEM), and X-ray diffraction (XRD) were carried out to study this luminescence quenching and it was discovered that there is close relationship between the luminescence intensity at 622 nm and structural properties. The cause of the concentration quenching is likely related to the polycrystalline growth as well as to the EuN formation.

Effect of Thermomechanical Processing on the Microstructure and Retained Austenite Stability during In Situ Tensile Testing Using Synchrotron X-Ray Diffraction of NbMoAl TRIP Steel

2011 ◽  
Vol 172-174 ◽  
pp. 741-746 ◽  
Author(s):  
Elena V. Pereloma ◽  
Lai Chang Zhang ◽  
Klaus Dieter Liss ◽  
Ulf Garbe ◽  
Jonathan Almer ◽  
...  
Keyword(s):  
Tensile Testing ◽  
Retained Austenite ◽  
Thermomechanical Processing ◽  
Critical Role ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
The Stability

In this work we compare and contrast the stability of retained austenite during tensile testing of Nb-Mo-Al transformation-induced plasticity steel subjected to different thermomechanical processing schedules. The obtained microstructures were characterised using optical metallography, transmission electron microscopy and X-ray diffraction. The transformation of retained austenite to martensite under tensile loading was observed by in-situ high energy X-ray diffraction at 1ID / APS. It has been shown that the variations in the microstructure of the steel, such as volume fractions of present phases, their morphology and dimensions, play a critical role in the strain-induced transition of retained austenite to martensite.

Properties of Mbe Grown Heterostructures of GaAs/InSb and InP/InSb.

1989 ◽  
Vol 145 ◽  
Author(s):  
M. T. Asom ◽  
E. A. Fitzgerald ◽  
F. A. Thiel ◽  
R. People ◽  
D. Eaglesham ◽  
...  
Keyword(s):  
Hall Effect ◽  
Lattice Mismatch ◽  
High Energy ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Energy Position ◽  
X Ray ◽  
Transmission Electron ◽  
Diffraction Peaks

AbstractWe have employed molecular beam epitaxy in the growth of InSb on GaAs and InP. The transport, optical and structural properties of the films were investigated by in-situ reflection high energy electron diffraction, Hall effect and temperature dependent Hall effect, photoluminescence, transmission electron microscopy and X-ray diffractometry techniques. We report mobilities of up to 32,000 cm2/volt-sec and free electron concentrations of 3x1016/cm3 at room temperature. We have discovered a new defect state in InSb with an energy position of Ec - 0.05 ± 0.006eV. Optical and structural measurements reveal that the differences in thermal expansion and lattice mismatch between the substrates and films results in the broadening of the X-ray diffraction peaks and the near gap photoluminescence linewidths. Furthermore, we observe band gap shifts to higher energies of 10meV and 20meV for growth on GaAs and InP, respectively.

scholarly journals Study of ZnO-CNT Nanocomposites in High-Pressure Conditions

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5330
Author(s):  
Laura-Madalina Cursaru ◽  
Sorina Nicoleta Valsan ◽  
Maria-Eliza Puscasu ◽  
Ioan Albert Tudor ◽  
Nicoleta Zarnescu-Ivan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Pressure ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron ◽  
Specific Morphology ◽  
Ft Ir ◽  
Nanocomposite Powders

Recently, carbon nanotubes (CNTs) have been used extensively to develop new materials and devices due to their specific morphology and properties. The reinforcement of different metal oxides such as zinc oxide (ZnO) with CNT develops advanced multifunctional materials with improved properties. Our aim is to obtain ZnO-CNT nanocomposites by in situ hydrothermal method in high-pressure conditions. Various compositions were tested. The structure and morphology of ZnO-CNT nanocomposites were analyzed by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry—thermogravimetry (DSC-TG), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM). These analyses showed the formation of complex ZnO-CNT structures. FT-IR spectra suggest possible interactions between CNT and ZnO. DSC-TG analysis also reveals the formation of some physical bonds between ZnO and CNT, through the appearance of endothermic peaks which could be assigned to the decomposition of functional groups of the CNT chain and breaking of the ZnO-CNT bonds. XRD characterization demonstrated the existence of ZnO nanocrystallites with size around 60 nm. The best ZnO:CNT composition was further selected for preliminary investigations of the potential of these nanocomposite powders to be processed as pastes for extrusion-based 3D printing.

Sign in / Sign up

Export Citation Format

Share Document