scholarly journals Rhodium influence on the microstructure and oxidation behaviour of aluminide coatings deposited on pure nickel and nickel based superalloy

2019 ◽  
Vol 38 (2019) ◽  
pp. 621-627
Author(s):  
Maryana Zagula-Yavorska
Keyword(s):  
Oxidation Resistance ◽  
Layer Structure ◽  
Thick Layer ◽  
Xrd Analysis ◽  
Pure Nickel ◽  
Nickel Based Superalloy ◽  
Aluminide Coatings ◽  
Refractory Elements ◽  
Main Components ◽  
Main Component

AbstractThe rhodium 0,5 μm thick layer was deposited on pure nickel and CMSX 4 Ni-based superalloy using the electroplating method. The rhodium coated substrates were aluminized by the CVD method. Oxidation resistance of nonmodified and rhodium modified coatings deposited both on nickel and CMSX 4 superalloy was compared. The triple-layer structure of rhodium modified coatings deposited on pure nickel was found. The β-(Ni,Rh)Al, rhodium doped γ'-Ni3Al and rhodium doped γ-Ni(Al) phases were the main components of the coatings on pure nickel. Two layers – additive and interdiffusion ones were identified in coatings deposited on CMSX 4 superalloy. TEM, SEM and XRD analysis revealed that β-(Ni,Rh)Al phase was the main component of the additive layer. Moreover Topologically Closed-Pack σ phases containing refractory elements in the β-(Ni,Rh)Al matrix of the interdiffusion layer were found. The rhodium modified aluminide coatings have better oxidation resistance than the nonmodified ones both on the pure nickel and CMSX 4 superalloy.

scholarly journals The Influence of Pd and Zr Co-Doping on the Microstructure and Oxidation Resistance of Aluminide Coatings on the CMSX-4 Nickel Superalloy

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7579
Author(s):  
Jolanta Romanowska ◽  
Jerzy Morgiel ◽  
Maryana Zagula-Yavorska
Keyword(s):  
Oxidation Resistance ◽  
Chemical Vapor ◽  
Nickel Superalloy ◽  
Aircraft Industry ◽  
Co Doping ◽  
Cvd Method ◽  
Aluminide Coatings ◽  
Refractory Elements ◽  
Nial Phase ◽  
Better Than

Pd + Zr co-doped aluminide coatings were deposited on the CMSX-4 nickel superalloy, widely used in the aircraft industry, in order to investigate their microstructure and improvement of oxidation resistance. Palladium was deposited by the electrochemical method, whereas zirconium and aluminum by the chemical vapor deposition (CVD) method. Coatings consist of two zones: the additive and the interdiffusion one. The additive zone contains β–(Ni,Pd)Al phase with some zirconium-rich precipitates close to the coating’s surface, whereas the interdiffusion zone consists of the same β–(Ni,Pd)Al phase with inclusions of refractory elements that diffused from the substrate, so called topologically closed-packed phases. Palladium dissolves in the β–NiAl phase and β–(Ni,Pd)Al phase is being formed. Pd + Zr co-doping improved the oxidation resistance of analysed coatings better than Pd mono-doping. Mechanisms responsible for this phenomenon and the synergistic effect of palladium and zirconium are discussed.

scholarly journals Oxidation Resistance of Modified Aluminide Coatings

2019 ◽  
Vol 253 ◽  
pp. 03006
Author(s):  
Jolanta Romanowska ◽  
Maryana Zagula-Yavorska ◽  
Łukasz Kolek
Keyword(s):  
Beneficial Effect ◽  
Oxidation Resistance ◽  
Noble Metals ◽  
Aluminide Coating ◽  
Pure Nickel ◽  
Scale Growth ◽  
Aluminide Coatings ◽  
Cyclic Oxidation Test ◽  
Nial Phase ◽  
Better Than

The application of protective aluminide coatings is an effective way to increase the oxidation resistance of the treated parts and prolongs their lifetime. The addition of small amount of noble metals (platinum or palladium) or reactive elements such as: hafnium, zirconium, yttrium and cerium has a beneficial effect on oxidation behavior. This beneficial effect includes an improvement of adhesion of alumina scales and reduction of oxide scale growth rate. Platinum and hafnium or zirconium modified aluminide coating were deposited on pure nickel using the electroplating and CVD methods. The coatings consisted of two layers: an outer, β-NiAl phase and the interdiffusion γ’-Ni3Al phase. Palladium dissolved in the whole coating, whereas hafnium and zirconium formed inclusions on the border of the layers. Samples were subjected to cyclic oxidation test at 1100 °C for 200h. Oxidation resistance of the palladium, Hf+Pd and Zr+Pd modified coatings deposited on pure nickel does not differ significantly, but is better than the oxidation resistance of the non-modified one.

OIL CONTENT AND CHEMICAL COMPOSITION IN THE PARTS OF OIL PALM FRUIT FROM 8 IOPRI VARIETIES

2018 ◽  
Vol 24 (2) ◽  
pp. 67-76
Author(s):  
Sujadi Sujadi ◽  
Hasrul Abdi Hasibuan ◽  
Meta Rivani ◽  
Abdul Razak Purba
Keyword(s):  
Fatty Acid ◽  
Palmitic Acid ◽  
Oil Palm ◽  
Oil Content ◽  
Mean Value ◽  
Oleic Acid Content ◽  
Palm Fruit ◽  
Fruit Samples ◽  
Main Components ◽  
Main Component

Fresh fruit bunches (FFB) consist of fruit be composed grade in few spikelet. Fruit at a spikelet can be distinguished into performed fruit namely internal fruit, middle fruit and outer fruit as soon as each section contain parthenocarpy fruits. This research was conducted for determine composition and content fatty acid of oil at internal fruit, middle, outer and parthenocarpy fruit from oil palm fruit. Samples of fruit came from 3 – 5 spikelet the central of FFB. Result showed that oil content of outer fruit (46.9 + 9.9)% trend higher be compared middle fruit (42.8 + 10.3)% and internal fruit (39.1 + 9.5)%. Parthenocarpy fruits have a low oil content (14.2 + 16.2)% except yellowish fruit trend high relatively oil content. The main components of fatty acid at outer fruit, middle and internal are palmitic acid, oleic, linoleic and stearic with mean value respectively (44.8 – 45.8)%, (37.6 – 38.0)%, (9.9 – 10.9)% and (4.6 – 4.8)%. Oil content at parthenocarpy fruit have amount main component of fatty acid with performed fruit but composition of palmitic acid (40.0 + 5.9)% and oleic (34.6 + 8.4)% lower while linoleic acid (16.9 + 8.5)% and linolenic (1.6 + 1.8)% higher be compared to performed fruit. Simalungun variety has the highest oil content in the part of fruit, with that PPKS 540 and La Mé respectively. PPKS 540 variety has the highest oleic acid content while PPKS 718 has the highest linoleic content.

scholarly journals The Influence of Aluminum Content on Oxidation Resistance of New-Generation ODS Alloy at 1200 °C

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1478 ◽  
Author(s):  
Luděk Stratil ◽  
Vít Horník ◽  
Petr Dymáček ◽  
Pavla Roupcová ◽  
Jiří Svoboda
Keyword(s):  
Oxidation Resistance ◽  
Cross Sections ◽  
Aluminum Content ◽  
Energy Dispersive Spectrometer ◽  
Oxide Dispersion Strengthened ◽  
Xrd Analysis ◽  
Al Content ◽  
Α Al2o3 ◽  
New Generation ◽  
Ods Alloy

The aim of the paper is to evaluate the effect of aluminum content on the oxidation resistance of new-generation of oxide dispersion strengthened (ODS) alloy at 1200 °C. Three grades of the alloy of chemical composition Fe-15Cr-xAl-4Y2O3 with different Al contents x = 0.3 wt.%, 2.0 wt.% and 5.5 wt.% are prepared by mechanical alloying. The alloys are consolidated by high temperature rolling followed by heat treatment. To study the oxidation resistance the samples are isothermally aged in the air for 1 h, 4 h, 16 h and 64 h at 1200 °C. The oxidation kinetics, composition and formation mechanism of the oxide layers are analyzed. The weight gain of prepared steels is estimated. The kinetics of oxidation is studied on metallographic cross-sections of the exposed samples by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) analysis. The oxides on the surfaces are identified by X‑ray diffraction (XRD) analysis. The Al content significantly enhances the oxidation resistance of the alloy. For a sufficiently high Al content in the alloy a compact oxide layer of α‑Al2O3 on the surface is formed, which significantly suppresses further oxidation process.

scholarly journals Behavioral and Antennal Responses of Tribolium confusum to Varronia globosa Essential Oil and Its Main Constituents: Perspective for Their Use as Repellent

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4393
Author(s):  
Cesar Auguste Badji ◽  
Jean Dorland ◽  
Lynda Kheloul ◽  
Dimitri Bréard ◽  
Pascal Richomme ◽  
...  
Keyword(s):  
Essential Oil ◽  
Tribolium Confusum ◽  
High Dose ◽  
Synthetic Chemicals ◽  
Stored Product Pest ◽  
Indigenous Plant ◽  
Main Components ◽  
Electroantennogram Recordings ◽  
The Individual ◽  
Main Component

Essential oils of aromatic plants represent an alternative to classical pest control with synthetic chemicals. They are especially promising for the alternative control of stored product pest insects. Here, we tested behavioral and electrophysiological responses of the stored product pest Tribolium confusum, to the essential oil of a Brazilian indigenous plant, Varronia globosa, collected in the Caatinga ecosystem. We analyzed the essential oil by GC-MS, tested the effects of the entire oil and its major components on the behavior of individual beetles in a four-way olfactometer, and investigated responses to these stimuli in electroantennogram recordings (EAG). We could identify 25 constituents in the essential oil of V. globosa, with anethole, caryophyllene and spathulenole as main components. The oil and its main component anethole had repellent effects already at low doses, whereas caryophyllene had only a repellent effect at a high dose. In addition, the essential oil abolished the attractive effect of the T. confusum aggregation pheromone. EAG recordings revealed dose-dependent responses to the individual components and increasing responses to the blend and even more to the entire oil. Our study reveals the potential of anethole and the essential oil of V. globosa in the management of stored product pests.

Oxidation resistance of nickel-based superalloy Inconel 600 in air at different temperatures

Rare Metals ◽  
2018 ◽  
Author(s):  
Dong-Sheng Li ◽  
Guang Chen ◽  
Dan Li ◽  
Qi Zheng ◽  
Pei Gao ◽  
...  
Keyword(s):  
Oxidation Resistance ◽  
Inconel 600 ◽  
Nickel Based Superalloy ◽  
Different Temperatures

Effects of Cr+ ion implantation on the oxidation of Ni3Al

1993 ◽  
Vol 8 (4) ◽  
pp. 734-740 ◽  
Author(s):  
M. Chen ◽  
S. Patu ◽  
J.N. Shen ◽  
C.X. Shi
Keyword(s):  
Oxidation Resistance ◽  
Layer Structure ◽  
Surface Region ◽  
Optical Microscope ◽  
Al Alloy ◽  
Temperature Oxidation ◽  
Intermediate Layers ◽  
Air Interface ◽  
Before And After ◽  
High Temperature Oxidation Behavior

Ni3Al samples were implanted with different doses of 150 keV Cr+ ions to modify the surface region. The high temperature oxidation behavior was tested. The surface layer structure was investigated by AES, TEM, XRD, and optical microscope before and after the test. The experimental results show that chromium ions turn a small amount of ordered superlattice Ni3Al phase into a disordered Ni–Al–Cr phase. Also there is a bcc chromium phase in the implanted sample. Implanted Ni3Al alloy has better oxidation resistance than the unimplanted one at 900 °C. The oxide layer is of a multilayer structure after 50 h oxidation, composed of a NiO inner layer, Cr2O3, spinel NiAl2O4 intermediate layers, and an α–Al2O3 external layer at the oxide/air interface. The α-Al2O3 and Cr2O3 are independent scale-like layers. The two protective layers improve the oxidation resistance significantly. The effects of implanted elements and possible reaction mechanisms are discussed.

Aluminide Coatings Formed on Fe–13Cr Steel at Low Temperature and its Oxidation Resistance

2007 ◽  
Vol 68 (5-6) ◽  
pp. 243-251 ◽  
Author(s):  
Zhaolin Zhan ◽  
Yedong He ◽  
Deren Wang ◽  
Wei Gao
Keyword(s):  
Low Temperature ◽  
Oxidation Resistance ◽  
Aluminide Coatings
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