(Invited) Understanding the Role of Al3+ in Accelerated Testing and Its Impact on the Protective Oxide Film of AA2060

ABSTRACTMetal CMP applications necessitate the formation of a protective oxide film in the presence of surface active agents, oxidizers, pH regulators and other chemicals to achieve global planarization. Formation and mechanical properties of the chemically modified metal oxide thin films in CMP determine the stresses develop at the interfaces delineating the stability and protective nature of the chemically altered films on the surface of the metal wafer. The balance between the stresses built in the film structure versus the mechanical actions provided during the process can be used to optimize the process variables and furthermore help define new planarization techniques for the next generation microelectronic device manufacturing. In this study, the preliminary studies were concentrated on the very well established tungsten CMP applications and furthermore, titanium CMP applications were presented as a part of surface nano-structuring methodology for biomedical applications by stressing the synergistic effect of protective metal oxide film of titanium in this advanced application.

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Microstructure and Hot Corrosion Properties of Laser Cladding of a Co-Base Alloy on the Leaf Surface of Gas Turbine

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.299-300.183 ◽

2011 ◽

Vol 299-300 ◽

pp. 183-187

Author(s):

Song Zhang ◽

Gong You Zhou ◽

Fang Hu ◽

Chun Hua Zhang ◽

Mao Cai Wang ◽

...

Keyword(s):

High Temperature ◽

Oxide Film ◽

Gas Turbine ◽

Hot Corrosion ◽

Carbon Dioxide Laser ◽

Base Alloy ◽

Stainless Steel Surface ◽

Protective Oxide ◽

Corrosion Properties ◽

Protective Oxide Film

The temperatures inside the gas turbine reach up to 1000°C, alloys used for gas turbine components must be oxidation, and corrosion resistant, and stable in structure under high temperature circumstances. A Co-based alloy was cladded on the 1Cr18Ni9Ti stainless steel surface using a high power carbon dioxide laser. The microstructure evolution and hot corrosion properties of samples in 75%Na2SO4+25%NaCl saline were investigated. The results show that the microstructures of the cladded layer is fine, and the hot corrosion resistance of the cladded layer was significantly improved because of the formation of a protective oxide film of CoO and CoO•Cr2O3. Under high temperature corrosive atmosphere, the high content of Co promoted the formation of the protective oxide film. The refinement of dendritic structures and the formation of Co-based alloy oxides lower the penetration rate of the sulphur ions that induce the intergranular corrosion.

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The Influence of Chrome in the Oxidation Process of Steels in Flowing LBE

Volume 1: Plant Operations, Maintenance, Engineering, Modifications and Life Cycle; Component Reliability and Materials Issues; Next Generation Systems ◽

10.1115/icone17-75025 ◽

2009 ◽

Author(s):

Taide Tan ◽

Yitung Chen

Keyword(s):

Oxidation Process ◽

Alloying Element ◽

Mesoscopic Scale ◽

Protective Oxide ◽

Scale Removal ◽

Chrome Oxide ◽

Protective Oxide Film ◽

Oxidation Model ◽

Stochastic Cellular Automaton

The role of the alloying element has been analyzed during the oxidation process of stainless steels in the flowing lead bismuth eutectic (LBE) environment. The growth of the protective oxide film of steels has been studied at a mesoscopic scale. The influence of chrome has been studied using the developed stochastic cellular automaton mesoscopic oxidation model, considering the formation of the chrome oxide and magnetite. During the oxidation process, the scale removal effect has been taken into account as well.

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High Temperature Corrosion of Microturbine Combustor Material

Volume 3: Turbo Expo 2007 ◽

10.1115/gt2007-27362 ◽

2007 ◽

Cited By ~ 2

Author(s):

Hiroshi Yakuwa ◽

Tadashi Kataoka

Keyword(s):

High Temperature ◽

Oxide Film ◽

High Temperature Corrosion ◽

Protective Oxide ◽

Lean Burn ◽

Protective Oxide Film ◽

Unburned Hydrocarbons ◽

The Rich ◽

Good Heat Resistance ◽

Good Heat

Two particular types of high temperature corrosion in a microturbine Rich-burn, Quick-mix, Lean-burn (RQL) combustor are discussed and reported in this paper. One type occurred in mixing tubes, part of fuel supply into the combustor. Dense concentrations of carbon monoxide and unburned hydrocarbons in a high temperature environment carburized the mixing tube, leaving it vulnerable to corrosion. The Co-based alloy was selected for the advantage of good heat resistance was exchanged for a Ni-Cr based alloy of good carburization resistance and the life of combustor successfully extended. The second type is a pitting corrosion on the inner wall of liner in the rich-burn zone. It is inferred that the corrosion was metal dusting caused from defects of the oxide film on the inner wall surface. As a countermeasure, a preoxidation step was applied to the combustor to maintain a protective oxide film for a longer period of time. This paper discusses the mechanisms and the countermeasures for these types of corrosion, which relate to carbon from the fuel origin activated in the fuel-rich environment in the combustor.

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STUDY OF THE STRUCTURE AND PHASE COMPOSITION OF THE OXIDE FILM ON THE SURFACE OF A LAYERED COATING OF THE Al-Ni SYSTEM

IZVESTIA VOLGOGRAD STATE TECHNICAL UNIVERSITY ◽

10.35211/1990-5297-2020-4-239-14-18 ◽

2020 ◽

pp. 14-18

Author(s):

V. G. Shmorgun ◽

A. I. Bogdanov ◽

V. P. Kulevich ◽

R. D. Evchits

Keyword(s):

Phase Composition ◽

Oxide Film ◽

Heating Temperature ◽

Atmospheric Oxygen ◽

Complex Oxide ◽

Protective Oxide ◽

Layered Coating ◽

Protective Oxide Film ◽

Temperature Heating ◽

High Temperature Heating

This work is aimed to the study of the structure and phase composition of the oxide film formed on the surface of the layered coating of the Al-Ni system during high-temperature heating. It was experimentally established that at the initial stages of heat treatment, as a result of the interaction of the Al-Ni system layered coating with atmospheric oxygen, separate sections of Al2O3 oxide are formed on its surface, which are agglomerates of plate crystals of α-modification of nanometer thickness, which increase and grow together with increasing exposure time continuous protective oxide film. An increase in the heating temperature leads to an intensification of oxidation processes and the formation of a complex oxide film of AlO and spinel NiAlO.

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The Role of H2O2 and K2S2O8 as Oxidizing Agents for Accelerated Corrosion Testing

CORROSION ◽

10.5006/3443 ◽

2020 ◽

Vol 76 (4) ◽

pp. 373-384

Author(s):

Mary E. Parker ◽

Russell Repasky ◽

Srishti Shrivastava ◽

Robert G. Kelly

Keyword(s):

Immersion Test ◽

Corrosion Testing ◽

Solution Ph ◽

Protective Oxide ◽

Accelerated Corrosion ◽

Oxidizing Agents ◽

Accelerated Corrosion Testing ◽

Protective Oxide Film ◽

Kinetics Of

In this work, the application of hydrogen peroxide (H2O2) and potassium persulfate (K2S2O8) in accelerated corrosion testing was considered. H2O2 is already used as an accelerant in the standard immersion test ASTM G110, and K2S2O8 is an oxidizing agent that shows promise for corrosion testing applications. A Koutecky-Levich approach was used to investigate the cathodic kinetics of both oxidizing agents as well as dissolved oxygen (O2). Cathodic kinetics for O2, H2O2, and S2O82− were faster when measured on a platinum electrode than when measured on an AA2060-T3 electrode. This difference was attributed to the additional limit to cathodic kinetics posed by the protective oxide film on aluminum. H2O2 was a more potent accelerant than K2S2O8 at a concentration of 0.1 M due to the faster cathodic kinetics of H2O2 on aluminum. However, K2S2O8 was more convenient to use in a laboratory setting due to its stability during storage. The severity of tests using K2S2O8 was increased by lowering the solution pH to 2.28. At the low solution pH, cathodic kinetics and extent of attack increased.

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