Oxidation Behavior of the Y56Al24Co20 Bulk Amorphous Alloy Containing Crystalline Composites at 325-450°C

2007 ◽  
Vol 539-543 ◽  
pp. 2117-2122 ◽  
Author(s):  
H.H. Hsieh ◽  
W. Kai ◽  
C.Y. Lin ◽  
Tsung Shune Chin
Keyword(s):  
Amorphous Alloy ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Rate Constants ◽  
Oxidation Kinetics ◽  
Oxidation Behavior ◽  
Bulk Amorphous Alloy ◽  
Temperature Dependent ◽  
Dry Air ◽  
Kinetics Of

The oxidation behavior of Y56Al24Co20 bulk metallic glass containing ~4.2% Y-rich particles was studied over the temperature range of 325-450oC in dry air. The results showed that the oxidation kinetics of the alloy followed the parabolic rate law at T≤375oC, with rate constants generally increased with temperature. Conversely, para-linear kinetics were observed at higher temperatures (T≥400oC). The scales formed on the Y-base amorphous composite were temperature dependent, consisting of exclusively yttrium oxides (Y2O3) at T≤375oC and of mostly Y2O3 and alumina (Al2O3) at temperatures. No evidence of any cobalt-containing oxide was found in the scale.

Air Oxidation Kinetics Study of Zr58Nb3Cu16Ni13Al10 Bulk Metallic Glass

2009 ◽  
Vol 283-286 ◽  
pp. 209-213 ◽  
Author(s):  
Dong Ya Huang ◽  
Xiang Jin Zhao ◽  
Tao Zhang ◽  
Vincent Ji
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Oxidation Kinetics ◽  
Glassy State ◽  
Supercooled Liquid ◽  
Isothermal Oxidation ◽  
Growth Speed ◽  
Air Oxidation ◽  
Two Stages ◽  
Kinetics Of

The isothermal oxidation behavior of Zr58Nb3Cu16Ni13Al10 bulk metallic glass (BMG) under dry air in the glassy state and the supercooled liquid state (SLS) was studied by the thermogravimetric method. The oxidation rate and thickness growth speed in the SLS were both hugely higher than in the glassy state. The oxidation kinetics of BMG in both states for 1.5 hours was different, the parabolic law was followed in the glassy state at 300°C and 350°C, contrarily the linear law was followed in SLS at 400 °C. After the oxidation for 126 hours in SLS, the oxidation kinetics possessed two stages, the linear stage and the parabolic stage. The diffusion of the Cu2+ ion and CuZr intermetallic alloys were detected by GIXRD.

scholarly journals Oxidation Behavior of a Pd43Cu27Ni10P20 Bulk Metallic Glass and Foam in Dry Air

2010 ◽  
Vol 41 (7) ◽  
pp. 1720-1725 ◽  
Author(s):  
W. Kai ◽  
I.F. Ren ◽  
B. Barnard ◽  
P.K. Liaw ◽  
M.D. Demetriou ◽  
...  
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Oxidation Behavior ◽  
Dry Air

Structural evaluation in Zr15Al5Ni57Y23bulk metallic glass under high pressure

2007 ◽  
Vol 1048 ◽  
Author(s):  
Gong Li ◽  
Yunpeng Gao ◽  
Tao Xu ◽  
Qin Jing ◽  
Jing Liu ◽  
...  
Keyword(s):  
High Pressure ◽  
Amorphous Alloy ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Nearest Neighbor ◽  
Structural Information ◽  
Bulk Amorphous Alloy ◽  
Atomic Configuration ◽  
Structural Evaluation ◽  
Atomic Distance

AbstractThe compression behavior of Zr15Al5Ni57Y23bulk metallic glass is investigated at room temperature usingin-situhigh pressure energy dispersive X-ray diffraction with a synchrotron radiation source. The structural information of the atomic configuration about Zr15Al5Ni57Y23bulk amorphous alloy such as coordination number (CN), neighbor atomic distance is gained by Fourier transformation under different pressure. The investigation shows that the structure of Zr15Al5Ni57Y23bulk metallic glass is stable under the pressure ranging from zero to 31.7 GPa, but the degree of short-range order changes by the pressure altering the second and the third nearest neighbor local atomic configuration of the amorphous alloy.

Initial Oxidation Behavior of Zr55Cu30Al10Ni5 Bulk Metallic Glass in Short-Term Stage

2011 ◽  
Vol 675-677 ◽  
pp. 209-212 ◽  
Author(s):  
Dong Ya Huang ◽  
Bin Wang ◽  
Vincent Ji ◽  
Tao Zhang
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Oxidation Kinetics ◽  
Liquid State ◽  
Glassy State ◽  
Supercooled Liquid ◽  
Short Term ◽  
Initial Oxidation ◽  
Oxygen Ions ◽  
Kinetics Of

The isothermal initial oxidation kinetics of Zr55Cu30Al10Ni5 bulk metallic glass in glassy state (lower than Tg = 685K) and in surpercooled liquid state (Tg = 685 K < T < Tx=774 K) is investigated under dry air by thermogravimetric method in short-term stage (for 1.5 hours). A protective parabolic law is followed in glassy state, except at 573 K where a linear law is followed. The self-limiting oxidation kinetics evolves from a short linear stage to a steady mild growth stage in supercooled liquid state at 723 K, which is induced mainly by crystallization and by the fast growth of dense scale. The growth of the scale is dominated by the formation of tetragonal-ZrO2 (t- ZrO2) in the range of 623 K - 673 K in glassy state for 1.5 hours. The activation energy of oxidation is mainly piloted by the diffusion of oxygen ions.

Crystallization Kinetics of the (Zr58Ni13.6Cu18Al10.4)Nb1 Bulk Metallic Glass

2006 ◽  
Vol 8 (8) ◽  
pp. 714-719 ◽  
Author(s):  
D. Qiao ◽  
C. Fan ◽  
P. K. Liaw ◽  
H. Choo
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Crystallization Kinetics ◽  
Kinetics Of

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.

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