Origin of Nickel Catalytic Particles in Carbon Nanotube Formation on a High-Carbon 25Cr–35Ni–Nb Cast Alloy
International audience
Oxidation Behavior of the Skutterudite Material Ce0.75Fe3CoSb12
Published in Oxidation of Metals
A thermoelectric generator is a powerful system used to produce electricity by the action of heat. The development of nanostructured thermoelectric materials is widespread with the objective to improve their efficiency. However, if these materials are used at high temperatures under oxidative atmosphere (e.g., in air), they may suffer degradation i...
High-Temperature Corrosion of HVAF-Sprayed Ni-Based Coatings for Boiler Applications
Published in Oxidation of Metals
The present study investigates the initial corrosion behaviour of HVAF-sprayed NiCr, NiAl and NiCrAlY coatings in two different environments, O2 + H2O and O2 + H2O + KCl at 600 °C for up to 168 h in order to evaluate the possibility of utilizing such coatings in biomass- and waste-fired boilers. SEM/EDX analysis showed that all coatings displayed a...
High-Temperature Oxidation Behavior of a Single-Layer IrAl Intermetallic Coating
Published in Oxidation of Metals
In order to improve the high-temperature service property of Ir, a well-bonded single-layer pure IrAl intermetallic coating was prepared on Ir by pack cementation followed by vacuum annealing treatment. The oxidation behavior of the IrAl coating was investigated by cyclic oxidation tests at 1400–2000 °C and compared with that of pure Ir. The result...
Characterization of the Oxide Scale Formed on T12 Water Wall Tube After Long-term Service in Supercritical Power Plant
Published in Oxidation of Metals
Oxide scale control is one of the critical maintenance issues in fossil fuel power plant. Hence, the water treatment of the feed water has been changed from all-volatile treatment (AVT) to oxygenated treatment (OT) by added some amount of oxygen in the system to form a stable oxide and minimize the scale growth rate. In this work, the oxide scales ...
The Effect of HVOF Bond Coating with APS Flash Coating on TBC Performance
Published in Oxidation of Metals
To study the benefit of ~ 50-µm-thick air-plasma-sprayed (APS) ‘flash’ bond coatings, NiCoCrAlYHfSi high-velocity oxygen fuel (HVOF) bond coatings were deposited on alloy 247 disk substrates with APS yttria-stabilized zirconia topcoatings. Using 1-h cycles at 1100 °C in air with 10% H2O and HVOF-only bond coatings as a baseline, APS flash coatings ...
The Corrosion of an Amorphous Fe70C10P10B5Mo5 Alloy in Various CO2/CO Mixed Gases at 500 °C
Published in Oxidation of Metals
The corrosion behavior of an Fe70C10P10B5Mo5 amorphous ribbon was investigated in various CO2/CO mixed gases within the oxygen partial pressure range 7.2 × 10−24 to 7.2 × 10−22 Pa at 500 °C. In general, the amorphous alloy exhibited exclusive oxidation throughout the study, and its oxidation kinetics followed the parabolic rate law. The parabolic r...
Influence of Nickel on the Oxidation Resistance at High Temperatures of Thin Chromium Coatings
Published in Oxidation of Metals
The oxidation behavior of four valve steels (X33CrNiMn23-8, X50CrMnNiNbN21-9, X53CrMnNiN20-8 and X55CrMnNiN20-8) covered with thin sputter-deposited coatings containing chromium and nickel was studied under isothermal and thermal shock conditions. It was determined that coated steels exhibit greater resistance against oxidation than steels with unm...
Study of SiO2 on Ni and Ti Silicide After Different Oxidation Techniques Investigated by XRR, SEM and Ellipsometry
Although silicide oxidation was studied 20years ago, the interest in obtaining a robust process for new applications remains significant today. Indeed, the new architectural development process requires dense and narrow spaces. In this study, attempts were made to bury a silicide layer under a protective silica layer in order to keep the physical a...
High-Temperature Corrosion of Ti–46Al–6Nb–0.5W–0.5Cr–0.3Si–0.1C Alloy in N2/0.1%H2S Gas
Published in Oxidation of Metals
Ti–46Al–6Nb–0.5W–0.5Cr–0.3Si–0.1C alloy was corroded at 800–1100 °C for 200 h in N2/0.1%H2S gas to characterize its corrosion behavior in an aggressive H2S-containing environment. The alloy displayed superior corrosion resistance because Ti and Al preferentially reacted with impurity oxygen in the gas to form TiO2 and Al2O3. It corroded primarily b...
