Isothermal oxidation behavior and growth kinetics of silicide coatings formed on Nb–1Zr–0.1C alloy

2015 ◽  
Vol 95 ◽  
pp. 100-109 ◽  
Author(s):  
Sanjib Majumdar ◽  
J. Kishor ◽  
B. Paul ◽  
R.C. Hubli ◽  
J.K. Chakravartty
Keyword(s):  
Growth Kinetics ◽  
Oxidation Behavior ◽  
Isothermal Oxidation ◽  
Kinetics Of

Isothermal Oxidation Resistance of Zr3[Al(Si)]4C6-Based Composite Ceramics at 1000-1300°C in Air

2018 ◽  
Vol 281 ◽  
pp. 444-449 ◽  
Author(s):  
Lei Yu ◽  
Hui Liu ◽  
Kai Liang ◽  
Zhen Di Zang ◽  
Jia Cheng Shi ◽  
...  
Keyword(s):  
Oxidation Resistance ◽  
Oxidation Behavior ◽  
Isothermal Oxidation ◽  
Oxide Thickness ◽  
Unit Surface Area ◽  
Composite Ceramics ◽  
Oxidation Rate Constant ◽  
Parabolic Law ◽  
Unit Surface ◽  
Kinetics Of

The isothermal oxidation behavior of Zr3[Al(Si)]4C6-ZrB2-ZrC composite ceramics at 1000-1300 °C in air has been investigated. The oxidation kinetics of the composites and generally follows a parabolic law. At the same oxidation temperature and time, the weight gain per unit surface area, oxidation rate constant and oxide thickness of the composites are higher than those of monolithic Zr3[Al(Si)]4C6 ceramic. With the incorporation of ZrB2 and ZrC, the oxidation resistance of the composites becomes poor. The surfaces of the oxide layer have a loose and porous structure, consisting of mainly ZrO2 and little mullite, and there are no dense oxide films preventing the inward diffusion of oxygen element effectively.

scholarly journals Oxidation Behavior of Zr-based Amorphous Alloys at 400˚- 450˚C in Air

2019 ◽  
Vol 6 (1) ◽  
pp. 24
Author(s):  
Triwikantoro Triwikantoro ◽  
Romdhoni Graha Pribadi ◽  
Fatimatul Munawaroh
Keyword(s):  
Crystallization Temperature ◽  
Amorphous Alloys ◽  
Oxidation Behavior ◽  
Intermetallic Phase ◽  
Isothermal Oxidation ◽  
Thermo Gravimetric ◽  
Parabolic Law ◽  
Thermo Gravimetric Analyzer ◽  
Kinetics Of ◽  
Dominant Phase

<em><span lang="EN-US">The study of oxidation behavior of amorphous alloys based on Zirconium with 2 variations in composition was carried out: Zr<sub>64.5</sub>Cu<sub>17</sub>Ni<sub>11</sub>Al<sub>7.5 </sub>and Zr<sub>69.5</sub>Cu<sub>12</sub>Ni<sub>11</sub>Al<sub>7.5 </sub>at temperatures of 400 - 450˚C in air. Amorphous Zr-based alloys were thermally characterized using Differential Scanning Calorimeter (DSC) to determine the crystallization temperature and glass transition temperature. The oxidation characterization was carried out using a Thermo gravimetric Analyzer (TGA) at temperatures of 400, 425, and 450˚C for 4 hours in air. The phase analysis of the oxidation product was identified using X-Ra</span><span>y Diffaction</span><span lang="EN-US"> (XRD). Based on DSC data the crystallization temperature for Zr<sub>64.5</sub>Cu<sub>17</sub>Ni<sub>11</sub>Al<sub>7.5</sub> and Zr<sub>69.5</sub>Cu<sub>12</sub>Ni<sub>11</sub>Al<sub>7.5 </sub>is 426 and 442˚C respectively. The oxidation kinetics of the two alloys follow parabolic law and the oxidation rate increases with the addition of temperature. Oxides formed during isothermal oxidation in the Zr<sub>64.5</sub>Cu<sub>17</sub>Ni<sub>11</sub>Al<sub>7.5 </sub>and Zr<sub>69.5</sub>Cu<sub>12</sub>Ni<sub>11</sub>Al<sub>7.5</sub> alloys are t-ZrO<sub>2</sub> (tetragonal) as the dominant phase and ZrO<sub>2</sub> (monoclinic) and CuO as the minor phase. The intermetallic phase is also formed in both samples, t-Zr<sub>2</sub>Ni and Zr<sub>2</sub>Cu.</span></em>

Oxidation Behavior of Ni3Al-8Cr-0.1B Alloy Containing Zr Addition

1988 ◽  
Vol 133 ◽  
Author(s):  
Guo Jiangting ◽  
Sun Chao ◽  
Li Hui ◽  
Guan Hengrong
Keyword(s):  
Phase Transformation ◽  
Weight Gain ◽  
Oxidation Behavior ◽  
Isothermal Oxidation ◽  
Surface Zone ◽  
Tree Roots ◽  
Parabolic Law ◽  
Zr Addition ◽  
Kinetics Of ◽  
Zirconium Addition

ABSTRACTThe isothermal oxidation behavior of Ni3A1 + 8Cr + 0.1B alloy containing zirconium addition was studied over a temperature range 850 to 1150°C and for periods up to 100 h. The results show that isothermal oxidation kinetics of the alloys at various temperatures obey a parabolic law. The addition of zirconium to Ni3A1-8Cr-0.1B alloy improves oxidation resistance at 850 to 950°C. However, the additive results in a considerable weight gain at 1050 to 1150°C. The structure of scale and phase transformation of the surface zone beneath the scale have been investigated. The addition of zirconium leads to the formation of adherent scale at all temperatures, since the internal oxides, like “tree roots” between the oxide scale and the substrate, are developed during oxidation.

Growth Kinetics and Isothermal Oxidation Behavior of Aluminide Pack Coatings on a Multiphase Mo–Si–B Alloy

2019 ◽  
Vol 92 (5-6) ◽  
pp. 423-437 ◽  
Author(s):  
Kwangsu Choi ◽  
Wonchul Yang ◽  
Kyeong-Ho Baik ◽  
Youngmoo Kim ◽  
Seong Lee ◽  
...  
Keyword(s):  
Growth Kinetics ◽  
Oxidation Behavior ◽  
Isothermal Oxidation

Growth kinetics and isothermal oxidation behavior of a Si pack cementation-coated Mo-Si-B alloy

2019 ◽  
Vol 489 ◽  
pp. 668-676 ◽  
Author(s):  
Kwangsu Choi ◽  
Wonchul Yang ◽  
Kyeong-Ho Baik ◽  
Youngmoo Kim ◽  
Seong Lee ◽  
...  
Keyword(s):  
Growth Kinetics ◽  
Oxidation Behavior ◽  
Isothermal Oxidation ◽  
Pack Cementation

Isothermal and Cyclic Oxidation Behavior of Turbine Blade Alloys

2006 ◽  
Author(s):  
N. S. Cheruvu ◽  
K. T. Chiang
Keyword(s):  
Turbine Blade ◽  
Cyclic Oxidation ◽  
Oxidation Behavior ◽  
Parabolic Rate Constant ◽  
Isothermal Oxidation ◽  
Isothermal Exposure ◽  
Temperature Oxidation ◽  
Rate Laws ◽  
Parabolic Rate ◽  
Kinetics Of

Oxidation behavior of two nickel-based turbine blade alloys has been investigated at three temperatures ranging from 950°C to 1066°C. Thermogravimetric analysis (TGA), isothermal exposure and cyclic oxidation tests were conducted on GTD-111 (Ni-14.1Cr-3.7W-9.2Co-1.5Mo-3.1A1-4.9Ti-0.02Cb-2.93Ta-0.11C) and IN-738 (Ni-16.0Cr-2.6W-8.1Co-1.6Mo-3.5A1-3.4Ti-0.7Cb-1.6Ta-0.10C) blade alloys. TGA results showed that the oxidation kinetics of both alloys obey parabolic rate laws. The GTD-111 material exhibited a higher parabolic rate constant than IN 738 at all temperatures investigated. Cyclic oxidation behavior of these alloys was compared by plotting the weight change results as a function of thermal cycles. Consistent with the TGA results, cyclic oxidation test results also showed that GTD-111 was less resistant to high-temperature oxidation as compared to the IN-738 alloy. To characterize the oxide scales, a series of short term isothermal oxidation tests were conducted and the spalled scale after oxidation exposure was collected and analyzed by energy-dispersive x-ray analysis (EDX) as a function of aging time. The composition of the scales varied between the alloys. The variation of oxidation behavior of these alloys is discussed with respect to the composition differences between the two alloys.

The Ordered Phase Formation in Ti-Al-Ga Alloys

1970 ◽  
Vol 28 ◽  
pp. 440-441
Author(s):  
Shiro Fujishiro ◽  
Harold L. Gegel
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Titanium Alloys ◽  
Growth Kinetics ◽  
Stoichiometric Composition ◽  
Good Potential ◽  
Alpha Titanium ◽  
Cold Rolled ◽  
Kinetics Of ◽  
Thermal Stability Of

Ordered-alpha titanium alloys having a DO19 type structure have good potential for high temperature (600°C) applications, due to the thermal stability of the ordered phase and the inherent resistance to recrystallization of these alloys. Five different Ti-Al-Ga alloys consisting of equal atomic percents of aluminum and gallium solute additions up to the stoichiometric composition, Ti3(Al, Ga), were used to study the growth kinetics of the ordered phase and the nature of its interface.The alloys were homogenized in the beta region in a vacuum of about 5×10-7 torr, furnace cooled; reheated in air to 50°C below the alpha transus for hot working. The alloys were subsequently acid cleaned, annealed in vacuo, and cold rolled to about. 050 inch prior to additional homogenization

Growth Kinetics of Quantum Size ZnO Particles

1998 ◽  
Vol 536 ◽  
Author(s):  
E. M. Wong ◽  
J. E. Bonevich ◽  
P. C. Searson
Keyword(s):  
Growth Kinetics ◽  
Ostwald Ripening ◽  
Chemical Potential ◽  
Colloidal Suspensions ◽  
Green Emission ◽  
Blue Shift ◽  
Constant Current ◽  
Mass Model ◽  
Zno Particles ◽  
Kinetics Of

AbstractColloidal chemistry techniques were used to synthesize ZnO particles in the nanometer size regime. The particle aging kinetics were determined by monitoring the optical band edge absorption and using the effective mass model to approximate the particle size as a function of time. We show that the growth kinetics of the ZnO particles follow the Lifshitz, Slyozov, Wagner theory for Ostwald ripening. In this model, the higher curvature and hence chemical potential of smaller particles provides a driving force for dissolution. The larger particles continue to grow by diffusion limited transport of species dissolved in solution. Thin films were fabricated by constant current electrophoretic deposition (EPD) of the ZnO quantum particles from these colloidal suspensions. All the films exhibited a blue shift relative to the characteristic green emission associated with bulk ZnO. The optical characteristics of the particles in the colloidal suspensions were found to translate to the films.

Growth kinetics of boride layers formed on GGG 40.3 ductile iron

2016 ◽  
Vol 58 (5) ◽  
pp. 418-421
Author(s):  
Fatma Ünal ◽  
Ahmet Topuz
Keyword(s):  
Growth Kinetics ◽  
Ductile Iron ◽  
Kinetics Of
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