Oxidation Behavior of Cu60Zr30Ti10 Bulk Metallic Glass

2005 ◽  
Vol 20 (6) ◽  
pp. 1396-1403 ◽  
Author(s):  
C.Y. Tam ◽  
C.H. Shek
Keyword(s):  
Metallic Glass ◽  
Oxide Layer ◽  
Bulk Metallic Glass ◽  
Photoelectron Spectroscopy ◽  
Oxidation Kinetics ◽  
Oxide Surface ◽  
X Ray ◽  
Rate Law ◽  
Cu Content ◽  
Surface Morphologies

The oxidation kinetics of Cu60Zr30Ti10 bulk metallic glass and its crystalline counterpart were studied in oxygen environment over the temperature range of 573–773 K. The oxidation kinetics, measured with thermogravimetric analysis, of the metallic glass follows a linear rate law between 573 and 653 K and a parabolic rate law between 673 and 733 K. It was also found that the oxidation activation energy of metallic glass is lower than that of its crystalline counterpart. The x-ray diffraction pattern showed that the oxide layer is composed of Cu2O, CuO, ZrO2, and metallic Cu. Cu enrichment on the topmost oxide layer of the metallic glass oxidized at 573 K was revealed by x-ray photoelectron spectroscopy while there was a decrease in Cu content in the innermost oxide layer. The oxide surface morphologies observed from scanning electron microscopy showed that ZrO2 granules formed at low temperatures while whiskerlike copper oxides formed at higher temperatures.

Oxidation-induced copper segregation in Cu60Zr30Ti10 bulk metallic glass

2006 ◽  
Vol 21 (4) ◽  
pp. 851-855 ◽  
Author(s):  
C.Y. Tam ◽  
C.H. Shek
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Photoelectron Spectroscopy ◽  
Surface Characterization ◽  
Subsurface Layer ◽  
Metallic Copper ◽  
Surface Region ◽  
Oxygen Atmosphere ◽  
X Ray Diffraction ◽  
X Ray

Copper segregation in a subsurface layer during annealing of Cu60Zr30Ti10 bulk metallic glass at 773 K under oxygen atmosphere has been investigated by x-ray diffraction, Auger electron spectroscopy, x-ray photoelectron spectroscopy, and scanning electron microscopy. The formation of metallic copper is strongly dependent on the annealing environment. Various oxides with metallic copper are formed after annealing in oxygen atmosphere, but only crystalline intermetallic phases are found under vacuum annealing. Besides, surface characterization results show that the sample annealed in oxygen and vacuum result in enrichment and depletion of Cu on the surface region, respectively.

Oxidation Behavior in Super-Plastic Microforming of Zr65Cu17.5Ni10Al7.5 Bulk Metallic Glass

2011 ◽  
Vol 117-119 ◽  
pp. 1377-1382
Author(s):  
Jun Wang ◽  
Guang Lan Liao ◽  
Qiang Yu ◽  
Tie Lin Shi
Keyword(s):  
Metallic Glass ◽  
Oxide Layer ◽  
Bulk Metallic Glass ◽  
Room Temperature ◽  
Oxidation Behavior ◽  
Amorphous Structure ◽  
Liquid Region ◽  
Silicon Mold ◽  
X Ray ◽  
Super Plastic

The influence of oxidation behavior on super-plastic microforming of bulk metallic glass Zr65Cu17.5Ni10Al7.5in the super-cooled liquid region was investigated. Samples were heated in air from room temperature to 395°C, 410°C, and 430°C, respectively, and kept under each temperature for 40 minutes. The increased weight of samples and the thickness of oxide layer were measured. Subsequently, the sample was compressed under 410°C with a micro gear silicon mold. In result, the oxide layer of the gear cracked and could be easily removed; also, the X-ray diffractometer showed that the gear core below the oxide layer remained an amorphous structure. It can be concluded that the oxidation behavior of Zr65Cu17.5Ni10Al7.5does not affect the super-plastic deformation, which indicates the feasibility of super-plastic microforming process in air.

Oxide Formation on the Bulk Metallic Glass Zr46.75Ti8.25Cu7.5Ni10Be27.5

1998 ◽  
Vol 554 ◽  
Author(s):  
M. Kiene ◽  
T. Strunskus ◽  
G. Hasse ◽  
F. Faupel
Keyword(s):  
Metallic Glass ◽  
Oxide Layer ◽  
Bulk Metallic Glass ◽  
Photoelectron Spectroscopy ◽  
Depth Profiling ◽  
Outward Diffusion ◽  
Oxide Layers ◽  
Preparation Conditions ◽  
Ti Oxides ◽  
Outermost Surface

AbstractIn this investigation depth profiling by Ar+ ion sputtering in combination with x-ray photoelectron spectroscopy was used to determine the thickness and the chemical composition of the oxide layers formed on the bulk metallic glass Zr46.75Tig8.25Cu7.5Ni10Be27.5 (V4) under different preparation conditions. The thickness of the oxide layer was in the range between 4 nm and 30 nm for samples oxidized in air at room temperature and annealed in air at 573 K for 15 hours, respectively. The oxide layers showed an enrichment of Be at the outermost surface followed by a Be, Zr and Ti rich phase. Cu and Ni are depleted within the whole oxide layer. BeO, ZrO2 and various Ti oxides were detected in the oxide layer, whereas Cu and Ni occurred only in a non-oxidized zerovalent state. Our data indicate that the oxidation is controlled by the inward and outward diffusion of the metallic components.

Effects of alloying on oxidation of Cu-based bulk metallic glasses

2005 ◽  
Vol 20 (10) ◽  
pp. 2647-2653 ◽  
Author(s):  
C.Y. Tam ◽  
C.H. Shek
Keyword(s):  
Metallic Glass ◽  
Oxidation Resistance ◽  
Metallic Glasses ◽  
Photoelectron Spectroscopy ◽  
Oxidation Kinetics ◽  
Bulk Metallic Glasses ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxide Phases ◽  
Porous Oxide

The oxidation kinetics and the effects of alloying on the oxidation behaviors of copper-based bulk metallic glasses were studied. The oxidation kinetics, oxide compositions, and structures were investigated by thermogravimetric analysis (TGA), x-ray diffraction, x-ray photoelectron spectroscopy (XPS), and scanning electron microscopy. Both the TGA results and the XPS depth profile measurements showed that the oxidation resistance of Cu60Zr30Ti10 bulk metallic glass was improved by adding Hf, but it deteriorated when it was alloyed with Y. The oxide phases were found to be ZrO2, Cu2O, and CuO in samples heated at 573 K while an additional metallic Cu phase was detected in the ones heated at 773 K. A porous oxide structure was observed in the (Cu0.6Zr0.3Ti0.1)98Y2 metallic glass oxidized at 673 K, and the poor oxidation resistance of the alloy is attributed to the porous structure.

Oxidation Kinetic and Diffusion Mechanism Study of a Zr-Based Bulk Metallic Glass Alloy

2011 ◽  
Vol 675-677 ◽  
pp. 193-196 ◽  
Author(s):  
Bin Wang ◽  
Dong Ya Huang ◽  
Zhe Chen ◽  
Nathalie Prud’homme ◽  
Vincent Ji
Keyword(s):  
Metallic Glass ◽  
Oxide Scale ◽  
Oxide Layer ◽  
Bulk Metallic Glass ◽  
Diffusion Mechanism ◽  
Oxidation Kinetic ◽  
Atomic Diffusion ◽  
Oxide Surface ◽  
Outward Diffusion ◽  
Oxidation Rates

Oxidation kinetic of a Zr55Cu30Al10Ni5 bulk metallic glass (BMG) and its crystalline counterpart were studied under dry artificial air (20% of O2 and 80% of N2) at 673 K by thermogravimetry analysis (TGA) method. According to TGA profiles, the oxidation kinetic in both amorphous and crystalline states followed a protective parabolic law. However, the oxidation rates for the amorphous alloy were obviously higher than those for the crystalline alloy. Pseudo-grazing incident X-Ray diffraction (GIXRD) has been carried out to identify the oxides nature and their crystalline structure. Tetragonal-ZrO2 dominated the oxide scale formed on both alloys (BMG and crystalline) at T = 673 K; meanwhile, a slight amount of Cu was detected on the oxide surface of studied BMG alloy. The atomic diffusion mechanism was investigated using a two-stage oxidation treatment to study oxide scale growth kinetics. The studied specimens were oxidized firstly under dry artificial air and then under 18O2 isotopic tracer gas for 1.5 hours respectively at 673 K. The evident solute penetration zone and ion diffusion characteristic through the oxide scale were determined by Cs+ secondary ion mass spectrometry (SIMS) depth profile. The results showed the mechanism of the oxide layer formation of both alloys was not only due to Oxygen ions diffusion from oxide surface to interior scale, but also to an outward diffusion of Zirconium ions from substrate to oxide layer and the ZrO2 oxide growth seemed to occur at the oxide/gas interface in our studied case.

Interactions of Ge Atoms with High- ê Oxide Dielectric Surfaces

2005 ◽  
Vol 879 ◽  
Author(s):  
Scott K. Stanley ◽  
John G. Ekerdt
Keyword(s):  
Oxide Layer ◽  
Photoelectron Spectroscopy ◽  
Chemical Vapor ◽  
Temperature Programmed Desorption ◽  
Tungsten Filament ◽  
X Ray ◽  
Dielectric Surfaces ◽  
Temperature Programmed ◽  
The Stability ◽  
Ge Nanocrystals

AbstractGe is deposited on HfO2 surfaces by chemical vapor deposition (CVD) with GeH4. 0.7-1.0 ML GeHx (x = 0-3) is deposited by thermally cracking GeH4 on a hot tungsten filament. Ge oxidation and bonding are studied at 300-1000 K with X-ray photoelectron spectroscopy (XPS). Ge, GeH, GeO, and GeO2 desorption are measured with temperature programmed desorption (TPD) at 400-1000 K. Ge initially reacts with the dielectric forming an oxide layer followed by Ge deposition and formation of nanocrystals in CVD at 870 K. 0.7-1.0 ML GeHx deposited by cracking rapidly forms a contacting oxide layer on HfO2 that is stable from 300-800 K. Ge is fully removed from the HfO2 surface after annealing to 1000 K. These results help explain the stability of Ge nanocrystals in contact with HfO2.

X-ray photoelectron spectroscopy study of the interaction of methanol with polycrystalline copper oxide surface

1996 ◽  
Vol 11 (7) ◽  
pp. 1605-1608 ◽  
Author(s):  
S. Badrinarayanan ◽  
A. B. Mandale ◽  
S. R. Sainkar
Keyword(s):  
Copper Oxide ◽  
Photoelectron Spectroscopy ◽  
Low Dose ◽  
Dissociative Adsorption ◽  
Methanol Decomposition ◽  
Oxide Surface ◽  
Polycrystalline Copper ◽  
Spectroscopy Study ◽  
Methanol Vapor ◽  
X Ray

Methanol decomposition on a clean polycrystalline copper oxide surface was studied by x-ray photoelectron spectroscopy (XPS). Methanol was adsorbed at 133 K and desorbed over a broad temperature range. When CuO was exposed to a very low dose of methanol vapor, dissociative adsorption takes place, leading to the formation of CH3O and H2O. This is attributed to the presence of preadsorbed oxygen on the CuO surface.

X-Ray Study of Pd40Cu30Ni10P20 Bulk Metallic Glass Brazing Filler for Ti-6Al-7Nb Alloy

2007 ◽  
pp. 1983-1987
Author(s):  
E. Miura ◽  
Gene E. Ice ◽  
E.D. Specht ◽  
J.W.L. Pang ◽  
Hidemi Kato ◽  
...  
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
X Ray

scholarly journals Surface Characteristics and Cell Adhesion Behaviors of the Anodized Biomedical Stainless Steel

2020 ◽  
Vol 10 (18) ◽  
pp. 6275
Author(s):  
Heng-Jui Hsu ◽  
Chia-Yu Wu ◽  
Bai-Hung Huang ◽  
Chi-Hsun Tsai ◽  
Takashi Saito ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Cell Culture ◽  
Stainless Steel ◽  
Cell Adhesion ◽  
Oxide Layer ◽  
Photoelectron Spectroscopy ◽  
X Ray ◽  
In Vitro Cell Culture ◽  
Cell Culture Assay

In this study, an electrochemical anodizing method was applied as surface modification of the 316L biomedical stainless steel (BSS). The surface properties, microstructural characteristics, and biocompatibility responses of the anodized 316L BSS specimens were elucidated through scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffractometry, transmission electron microscopy, and in vitro cell culture assay. Analytical results revealed that the oxide layer of dichromium trioxide (Cr2O3) was formed on the modified 316L BSS specimens after the different anodization modifications. Moreover, a dual porous (micro/nanoporous) topography can also be discovered on the surface of the modified 316L BSS specimens. The microstructure of the anodized oxide layer was composed of amorphous austenite phase and nano-Cr2O3. Furthermore, in vitro cell culture assay also demonstrated that the osteoblast-like cells (MG-63) on the anodized 316L BSS specimens were completely adhered and covered as compared with the unmodified 316L BSS specimen. As a result, the anodized 316L BSS with a dual porous (micro/nanoporous) oxide layer has great potential to induce cell adhesion and promote bone formation.

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