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.

Isothermal Oxidation Behavior of a New Directionally Solidified Ni-Base Superalloy in Air at Different Temperature

2010 ◽  
Vol 654-656 ◽  
pp. 538-541
Author(s):  
Lei Wang ◽  
Yan Huang ◽  
Zhuo Zhao ◽  
Yang Liu ◽  
Jian Tao Wu ◽  
...  
Keyword(s):  
Oxidation Resistance ◽  
Oxidation Behavior ◽  
Isothermal Oxidation ◽  
Oxidation Behaviour ◽  
Diffusion Activation Energy ◽  
Directionally Solidified ◽  
Temperature Range ◽  
Parabolic Law ◽  
Diffusion Activation ◽  
Base Superalloy

The isothermal oxidation behaviour under static atmosphere of a new directionally solidified Ni-base superalloy was investigated. The results showed that the oxidation kinetics curves of the alloy follow parabolic law in the temperature range of 750-950°C. The diffusion activation energy Q is to be about 244.86 kJ•mol-1 and the oxidation within this temperature range is mainly controlled by Cr3+ diffusion among Cr2O3 oxidation film. The oxidation resistance grade of the alloy is perfect anti-oxidation within 750-850°C, and anti-oxidation within 900-950°C. The oxidation film can be divided into TiO2, Cr2O3+TiTaO4+NiCr2O4, Al2O3 and TiN layers, from the surface to inside. Priority oxidation and the inside oxidation of Al are considered with the oxidation of Ti and the depletion of Cr, and it is the key point for the improving of oxidation resistance.

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.

scholarly journals Oxidation behavior of non-stoichiometric (Zr,Hf,Ti)Cx carbide solid solution powders in air

2021 ◽  
Author(s):  
Huilin Lun ◽  
Yi Zeng ◽  
Xiang Xiong ◽  
Ziming Ye ◽  
Zhongwei Zhang ◽  
...  
Keyword(s):  
Solid Solution ◽  
Oxidation Resistance ◽  
Oxidation Behavior ◽  
Group Iv ◽  
Hypersonic Vehicles ◽  
Metal Carbides ◽  
Initial Oxidation ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Kinetics Of

AbstractMulti-component solid solutions with non-stoichiometric compositions are characteristics of ultra-high temperature carbides as promising materials for hypersonic vehicles. However, for group IV transition-metal carbides, the oxidation behavior of multi-component non-stoichiometric (Zr,Hf,Ti)Cx carbide solid solution has not been clarified yet. The present work fabricated four kinds of (Zr,Hf,Ti)Cx carbide solid solution powders by free-pressureless spark plasma sintering to investigate the oxidation behavior of (Zr,Hf,Ti)Cx in air. The effects of metallic atom composition on oxidation resistance were examined. The results indicate that the oxidation kinetics of (Zr,Hf,Ti)Cx are composition dependent. A high Hf content in (Zr,Hf,Ti)Cx was beneficial to form an amorphous Zr-Hf-Ti-C-O oxycarbide layer as an oxygen barrier to enhance the initial oxidation resistance. Meanwhile, an equiatomic ratio of metallic atoms reduced the growth rate of (Zr,Hf,Ti)O2 oxide, increasing its phase stability at high temperatures, which improved the oxidation activation energy of (Zr, Hf, Ti)Cx.

scholarly journals Influence of Grain Refinement on Oxidation Behavior of Two-Phase Cu–Cr Alloys at 973–1,073 K in Air

2016 ◽  
Vol 35 (10) ◽  
pp. 1005-1011
Author(s):  
T. J. Pan ◽  
J. Chen ◽  
Y. X. He ◽  
W. Wei ◽  
J. Hu
Keyword(s):  
Grain Size ◽  
Spatial Distribution ◽  
Oxidation Behavior ◽  
Second Phase ◽  
Two Phase ◽  
Reactive Component ◽  
Parabolic Law ◽  
Second Phase Particles ◽  
Kinetics Of ◽  
Lower Oxidation

AbstractThe oxidation behavior of grain-refined Cu–7.0 Cr alloy (GR Cu–7.0 Cr) in air at 973–1,073 K was investigated in comparison with normal casting Cu–7.0 Cr alloy (CA Cu–7.0 Cr). The oxidation of CA Cu–7.0 Cr alloy nearly followed parabolic law, while the oxidation kinetics of GR Cu–7.0 Cr slightly deviated from parabolic law. Both alloys almost produced multi-layered scales consisting of the outer layer of CuO and the inner layer of mixed Cr2O3 and Cu2O oxides plus internal oxidation zones of chromium. The grain-refined Cu–7.0 Cr alloy produced a more amount of Cr2O3 in the inner layer of the scale, and thus was oxidized at much lower oxidation rate than that of CA Cu–7.0 Cr with normal grain size. The experimental results indicated that the differences in oxidation behavior between two alloys may be ascribed to the different size and spatial distribution of the second-phase particles and the reactive component contents in localized zone.

Oxidation Behavior of As-Forged Fe-25wt%Cr Alloys at 1100°C in Air

2011 ◽  
Vol 695 ◽  
pp. 348-352 ◽  
Author(s):  
Hui Xie ◽  
Lei Jia ◽  
Xiao Feng Zhang ◽  
Zhen Lin Lu
Keyword(s):  
Oxidation Behavior ◽  
Oxidation Process ◽  
Hot Forging ◽  
Oxygen Ions ◽  
Second Stage ◽  
Parabolic Law ◽  
Transport Velocity ◽  
Fast Transport ◽  
Kinetics Of ◽  
Oxidation Scale

Fe-25wt%Cr alloys were fabricated by combining Powder Metallurgy (PM) with hot-forging treatment, and their oxidation behavior at 1100°C in air was investigated systematically by using XRD, SEM and EDS, respectively. The results showed that a composite oxidation scale containing both Cr2O3and FeCr2O4formed on the surface of as-forged Fe-25wt%Cr alloys after oxidation at 1100°C in air for 100 hours. The oxidation process of Fe-Cr alloys could be obviously divided into two different stages, and the kinetics of two-stage oxidation agreed well with the parabolic law. The first could be corresponding to the formation of protective Cr2O3layer, while the second could be thought as the growth of FeCr2O4and the further oxidation of the inner Cr2O3oxidation scale. The faster oxidation rate in the second stage could be attributed to both the diffusion of iron ions rapider than that of Cr in the Cr2O3layer and the fast transport velocity of oxygen ions along the cracks.

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

Air Oxidation Behavior of Two Ti-Base Alloys Synthesized by HIP

2016 ◽  
Vol 35 (4) ◽  
pp. 353-359
Author(s):  
S. Liu ◽  
Q. Q. Guo ◽  
L. L. Liu ◽  
L. Xu ◽  
Y. Y. Liu
Keyword(s):  
Oxidation Kinetics ◽  
Oxidation Behavior ◽  
Hot Isostatic Pressing ◽  
Air Oxidation ◽  
Isostatic Pressing ◽  
Parabolic Law ◽  
Cast Alloys ◽  
Ternary Additions ◽  
Kinetics Of

AbstractThe oxidation behavior of Ti-5Al-2.5Sn and Ti-6Al-4V produced by hot isostatic pressing (HIP) has been studied at 650–850°C in air for 24 h. The oxidation kinetics of both alloys followed the parabolic law with good approximation, except for Ti-5Al-2.5Sn oxidized at 850°C. Multi-layered scales formed on both alloys at 750°C and 850°C. Ternary additions of Sn and V accounted for the different morphology of the scales formed on these two alloys. In addition, the oxidation behavior of HIP alloys is compared with that of the corresponding cast alloys and the scaling mechanism is discussed.

Isothermal Oxidation Behavior of Ni Base Superalloy DM02 for High Temperature Dies

2007 ◽  
Vol 546-549 ◽  
pp. 1253-1256
Author(s):  
Qing Li ◽  
Jin Xia Song ◽  
Cheng Bo Xiao ◽  
Shi Yu Qu ◽  
Ding Gang Wang ◽  
...  
Keyword(s):  
Weight Gain ◽  
High Temperature ◽  
Oxide Scale ◽  
Oxidation Resistance ◽  
Growth Mechanism ◽  
Oxidation Kinetics ◽  
Oxidation Behavior ◽  
Isothermal Oxidation ◽  
Good Oxidation Resistance ◽  
Base Superalloy

The isothermal oxidation behavior of a new developed Ni base superalloy named DM02 for high temperature dies was studied in this paper. The dynamic curve was achieved by monitoring weight gain of the alloy as a function of time. The results showed that the alloy had fairly good oxidation resistance at 1050°C and 1100°C. The oxidation kinetics at both 1050°C and 1100°C followed parabolic rules in segment. It has been found that the oxidation of the alloy was controlled by multi-oxides of (Ni, Co)O, (Ni, Co)Al2O4, and NiWO4, growth mechanism in the primary stage, and by Al2O3, NiAl2O4 growth mechanism in the following stage. After oxidation at 1050°C for 100h, the oxide scale of the alloy was mainly composed of two areas. Some were thin uniform (Ni， Co)Al2O4(outer)/Al2O3 (inner) composites scale and others were multi-layer oxide scale of ( Ni,Co)O / multi-oxides (mainly NiWO4、NiO and NiAl2O4.) /Al2O3.

Improvement in the Oxidation Resistance of β-SiAlON Ceramics Produced from Mechanically Milled Powders

2012 ◽  
Vol 18-19 ◽  
pp. 281-290
Author(s):  
Onur Eser ◽  
S. Kurama
Keyword(s):  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
Oxidation Behavior ◽  
Oxidation Process ◽  
Isothermal Oxidation ◽  
High Energy ◽  
Particle Sizes ◽  
Temperature Oxidation ◽  
Dry Air ◽  
Milled Powders

In the present study the oxidation behavior of β-SiAlON ceramics, which were produced from conventional and high energy mechanical milled powders, was investigated. High energy mechanically milled powders have lower particle sizes ( 130 nm) than those of conventional powders (216 nm) and fully densified at lower temperatures with less amount of additives. The amount of additive is an important parameter to improve the high temperature oxidation resistance of SiAlON ceramics. The cyclic and isothermal oxidation tests were carried out at 1300 and 1400°C in dry air environment. The weight gain of oxidized samples was measured during the oxidation process. The alteration of oxide layer was analyzed by XRD and SEM. The results indicate that oxidation resistance of the samples produced from mechanically milled powders with less amount of additive is higher than that of conventional one. Therefore, β-SiAlON ceramics which were sintered at 100°C lower temperatures with less amount of additive (3.5 wt. % Y2O3), showed a better oxidation resistance.

Sign in / Sign up

Export Citation Format

Share Document