The Effect of Various Oxide Dispersions on the Oxidation Resistance of Fe3Al

1994 ◽  
Vol 364 ◽  
Author(s):  
B. A. Pint ◽  
K. B. Alexander ◽  
P. F. Tortorelli
Keyword(s):  
Powder Metallurgy ◽  
Oxidation Resistance ◽  
Cyclic Oxidation ◽  
Oxidation Behavior ◽  
Base Alloy ◽  
Hot Extrusion ◽  
Powder Metallurgy Technique ◽  
Scale Adhesion ◽  
Fecral Alloy ◽  
Oxidation Testing

AbstractOxide-dispersed Fe-28at.%Al-2%Cr alloys were produced by a powder metallurgy technique followed by hot extrusion. Yttria and ceria were added to the base alloy to assess the effect of these dopants on the oxidation behavior. The amount of dopant was varied from 0.05–0.5 at.% Y in a series of Y2O2-dispersed alloys. Isothermal and cyclic oxidation testing was conducted at temperatures from 800˚ to 1300˚C. A Ce02 addition was detrimental to the oxidation behavior. The Y2O3 improved the (α-Al2O3 scale adhesion relative to an undoped alloy, but was not as effective as similar additions to an oxide-dispersed FeCrAl alloy.

Enhanced Oxidation Resistance and Microhardness of Ni-Ysz Composites Via the Forging in Air

2018 ◽  
Vol 55 (1) ◽  
pp. 118-123
Author(s):  
O.Yu. Kurapova ◽  
E.N. Solovyeva ◽  
I.V. Lomakin ◽  
V.M. Ushakov ◽  
I.Yu. Archakov ◽  
...  
Keyword(s):  
Powder Metallurgy ◽  
Oxidation Resistance ◽  
Vickers Hardness ◽  
Oxidation Behavior ◽  
Vacuum Annealing ◽  
Ceramic Coatings ◽  
Industrial Applications ◽  
Powder Metallurgy Technique ◽  
Significant Progress ◽  
Available Information

Abstract Nickel-ceramics composites are very promising materials for various industrial applications. Significant progress was achieved in the field of composite nickel-ceramic coatings development. However, in case of bulk nickel-ceramics composites the available information is quite insufficient. In this study the effect of forging on the microstructure, oxidation resistance, and microhardness of Ni-8Y2O3-92ZrO2 (Ni-YSZ) composites was revealed. Nickel-YSZ composites were manufactured by powder metallurgy technique with following vacuum annealing at 1250 °C; in addition, forging at 1000 °C was applied. Oxidation behavior was studied by termogravimetry in air. The microstructure of the composites was investigated via SEM, XRD, and EBSD analysis. It was shown that forged composites do not undergo oxidation in the temperature range 20-950 °C. Forged Ni-YSZ composites exhibited improved Vickers hardness (HV) compared to bulk nickel.

STUDY ON CYCLIC OXIDATION RESISTANCE OF HIGH NIOBIUM CONTAINING TiAl BASE ALLOY WITH ERBIUM

2013 ◽  
Vol 49 (11) ◽  
pp. 1369 ◽  
Author(s):  
Ziqi GONG ◽  
Ziyong CHEN ◽  
Lihua CHAI ◽  
Zhilei XIANG ◽  
Zuoren NIE
Keyword(s):  
Oxidation Resistance ◽  
Cyclic Oxidation ◽  
Base Alloy

Effects of Yttrium on Cyclic Oxidation Resistance of Co-10Cr-5Al Alloy at 700 °C

2014 ◽  
Vol 528 ◽  
pp. 25-29
Author(s):  
Ling Yun Bai ◽  
Xian Chao Xu ◽  
Jun Huai Xiang ◽  
Yun Xiang Zheng ◽  
Jun Wang
Keyword(s):  
Oxide Scale ◽  
Oxidation Resistance ◽  
Oxidation Rate ◽  
Cyclic Oxidation ◽  
Oxidation Behavior ◽  
Adhesive Property ◽  
Complex Mode ◽  
Rate Law ◽  
Parabolic Rate

The cyclic oxidation behavior of Co-10Cr-5Al alloys in atmosphere at 700 °C was investigated. The addition of 0.3 at.% Y changed the oxidation behavior from the approximate parabolic rate law to complex mode. The scale grown on the surface of Co-10Cr-5Al cracked seriously, while the oxide scale the Y doped alloy had better adhesive property. Yttrium doped in the sample promoted the forming of continuous Al2O3layer and decreased the oxidation rate of Co-10Cr-5Al alloys.

Sliding wear behaviour of Al-Si alloy–fly ash composites produced by powder metallurgy technique

2017 ◽  
Vol 69 (2) ◽  
pp. 241-247 ◽  
Author(s):  
H. Siddhi Jailani ◽  
A. Rajadurai ◽  
B. Mohan ◽  
T. Sornakumar
Keyword(s):  
Cast Iron ◽  
Fly Ash ◽  
Powder Metallurgy ◽  
Alloy Powder ◽  
Base Alloy ◽  
Wear Behaviour ◽  
Damping Capacity ◽  
Powder Metallurgy Technique ◽  
Sliding Speed ◽  
Content Type

Purpose Metal matrix composites (MMCs) are commonly used in many aerospace and industrial applications. MMCs possess significantly improved properties including high specific strength, specific modulus, damping capacity and good wear resistance compared to unreinforced alloys. The purpose of this paper is to describe the tribological studies of Al-Si alloy–fly ash composites manufactured using powder metallurgy technique. Design/methodology/approach Al-Si (12 Wt.%) alloy–fly ash composites were developed using powder metallurgy technique. Al-Si alloy powder was used as matrix material, and the fly ash was used as reinforcement. The particle size of Al-Si alloy powder was in the range of 75-300 μm, and the fly ash was in the range of 1-15 μm. The friction and wear characteristics of the composites were studied using a pin-on-disc set up. The test specimen was mated against cast iron disc, and the tests were conducted with the loads of 10, 20 and 30 N, sliding speeds of 0.5, 1 and 1.5 m/s for a sliding distance of 2,000 m. Findings The effects of load and sliding speed on tribological properties of the base alloy and Al-Si alloy–fly ash composites pins on sliding with cast iron disc are evaluated. The wear rate of Al-Si alloy–fly ash composites is lower than that of base alloy, and it increases with increasing load and sliding speed. The coefficient of friction of Al-Si alloy–fly ash composites is increased as compared with base alloy. Practical implications The development of Al-Si alloy–fly ash composites produced by powder metallurgy technique will modernize the automobile and other industries because near net shape at low cost and good mechanical properties are obtained. Originality/value There are few papers available on the development and tribological studies of Al-Si alloy–fly ash composites produced by powder metallurgy technique.

An Effective Approach to Improve the Oxidation Resistance of Ti-6Al-4V Alloy by Combination of Phosphorization and Silica Coating

2011 ◽  
Vol 148-149 ◽  
pp. 534-537
Author(s):  
Chun Xiang Gao
Keyword(s):  
Oxidation Resistance ◽  
Cyclic Oxidation ◽  
Oxidation Behavior ◽  
Sol Gel ◽  
Synergetic Effect ◽  
Silica Coating ◽  
Dip Coating ◽  
Sio2 Coating ◽  
Amorphous Sio2 ◽  
Dip Coating Technique

A very effective approach to improve the oxidation resistance of Ti-6Al-4V alloy was proposed. The Ti-6Al-4V alloy was firstly phosphated and then coated by silica using sol-gel dip-coating technique. A duplex layer of TiP2O7 and amorphous silica was synthesized at the alloy surface. The isothermal and cyclic oxidation behavior of the treated alloy with silica coating and the corresponding bare alloy was investigated at 600 oC in static air to investigate the synergetic effect of phosphorization and amorphous SiO2 coating on the oxidation resistance of the alloy. The isothermal and cyclic oxidation resistances of the alloy were greatly improved.

Cyclic oxidation behavior and oxide scale adhesion of Al/NiCrAlY coating on pure titanium alloy

2017 ◽  
Vol 729 ◽  
pp. 679-687 ◽  
Author(s):  
Xue Gong ◽  
Ruirun Chen ◽  
Qi Wang ◽  
You Wang ◽  
Nannan Zhang ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Oxide Scale ◽  
Cyclic Oxidation ◽  
Oxidation Behavior ◽  
Pure Titanium ◽  
Scale Adhesion ◽  
Nicraly Coating

Cyclic Oxidation Resistance of Co-10Cr-5Al-0.3Y Alloy at 800 oc

2014 ◽  
Vol 1015 ◽  
pp. 505-508
Author(s):  
Ling Yun Bai ◽  
Hong Hua Zhang ◽  
Huai Shu Zhang ◽  
Yun Xiang Zheng ◽  
Jun Huai Xiang
Keyword(s):  
Oxidation Resistance ◽  
Oxidation Rate ◽  
Cyclic Oxidation ◽  
Oxidation Behavior ◽  
Oxidation Process ◽  
Oxidation Mechanism ◽  
Local Zone

The cyclic oxidation behavior of Co-10Cr-5Al alloys with and without 0.3 at% Y doped in atmosphere at 800oC was investigated. The addition of 0.3 at.% Y increased the oxidation rate of the alloy and changed the oxidation mechanism. The scales grown the alloys with and without Y were both composed of an outer Co2O3layer and an inner complex layer of Al2O3, Co2O3and Cr2O3, except that the addition of 0.3 at% Y enhanced the adhesion of the scale. 0.3 at% Y agglomerated in local zone which accelerated the oxidation rate and was not conductive to the oxidation process of the Co-10Cr-5Al alloy.

Oxidation resistance of Mo(Si1−xAlx)2 nanocrystalline films and characterization of their oxide scales by electrochemical impedance spectroscopy

RSC Advances ◽  
2014 ◽  
Vol 4 (99) ◽  
pp. 55696-55708 ◽  
Author(s):  
Jiang Xu ◽  
ZhengYang Li ◽  
Paul Munroe ◽  
Zong-Han Xie
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Oxidation Resistance ◽  
Cyclic Oxidation ◽  
Oxidation Behavior ◽  
Electrochemical Impedance ◽  
Oxide Scales ◽  
Nanocrystalline Films

To explore the influence of Al alloying on the oxidation resistance of MoSi2, four Mo(Si1−xAlx)2 nanocrystalline films were fabricated on Ti–6A1–4V substrates and their cyclic oxidation behavior was characterized.

Evaluation of Alumina-Forming Austenitic Foil for Advanced Recuperators

2010 ◽  
Author(s):  
Bruce A. Pint ◽  
Michael P. Brady ◽  
Yukinori Yamamoto ◽  
Michael L. Santella ◽  
Philip J. Maziasz ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Oxidation Resistance ◽  
Creep Strength ◽  
Oxidation Behavior ◽  
Alumina Scale ◽  
Exhaust Gas ◽  
Commercial Batch ◽  
Oxidation Testing ◽  
Thick Foil

A corrosion- and creep-resistant austenitic stainless steel has been developed for advanced recuperator applications. By optimizing the Al and Cr contents, the alloy is fully austenitic for creep strength while allowing the formation of a chemically-stable external alumina scale at temperatures up to 900°C. An alumina scale eliminates long-term problems with the formation of volatile Cr oxy-hydroxides in the presence of water vapor in exhaust gas. As a first step in producing foil for primary surface recuperators, three commercially cast heats have been rolled to ∼100μm thick foil in the laboratory to evaluate performance in creep and oxidation testing. Results from initial creep testing are presented at 675° and 750°C showing excellent creep strength compared to other candidate foil materials. Laboratory exposures in humid air at 650°-800°C have shown acceptable oxidation resistance. Similar oxidation behavior was observed for sheet specimens of these alloys exposed in a modified 65kW microturbine for 2,871h. One composition that showed superior creep and oxidation resistance has been selected for preparation of a commercial batch of foil.

Effects of Yttrium on Cyclic Oxidation Resistance of Co-10Cr-5Al Alloy

2013 ◽  
Vol 785-786 ◽  
pp. 844-847
Author(s):  
Jun Huai Xiang ◽  
Xian Chao Xu ◽  
Ling Yun Bai ◽  
Yun Xiang Zheng ◽  
Huai Shu Zhang
Keyword(s):  
Oxidation Resistance ◽  
Oxidation Kinetics ◽  
Oxidation Rate ◽  
Cyclic Oxidation ◽  
Oxidation Behavior ◽  
Oxidation Process ◽  
Local Zone ◽  
Rate Law ◽  
Parabolic Rate

The cyclic oxidation behavior of Co-10Cr-5Al alloys with and without Y in atmosphere at 800 °C was investigated. The addition of 0.3 at.% Y increased the oxidation rate of the alloy and changed the behavior from irregular oxidation kinetics to approximate parabolic rate law. The scales grown the alloys with and without Y were both composed of an outer Co2O3layer and an inner complex layer of Al2O3, Co2O3and Cr2O3, except that the addition of Y impaired the adhesion of the scale. Over-doped Y agglomerated in local zone plays an adverse role in the oxidation process by accelerating the oxidation rate.

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