The Effect of Yttrium Ion Implantation on the High Temperature Oxidation Properties of NiAl

1990 ◽  
Vol 213 ◽  
Author(s):  
B.A. Pint ◽  
A. Jain ◽  
L.W. Hobbs
Keyword(s):  
High Temperature ◽  
Oxidation Rate ◽  
High Temperature Oxidation ◽  
Aluminum Content ◽  
Cyclic Testing ◽  
Cation Diffusion ◽  
Temperature Oxidation ◽  
Oxidation Properties ◽  
Yttrium Ion ◽  
Very High

ABSTRACTNiAl was ion implanted with yttrium (2×1016 cm−2) in order to study its effect on the very high temperature (1000–1500°C) oxidation properties. At 1000°C, implanted Y stabilizes the faster growing θ-Al2O3 phase, thus slightly increasing the oxidation rate. At 1200°C, where predominantly α-Al2 O3 is formed with and without Y, there is a factor of 4 reduction in the oxidation rate. However at higher than 1200°C, there is little effect by Y on the oxidation rate. Cyclic testing showed that the Y implant had an imperfect and short-lived improvement on adherence relative to other Y-containing alloys. Variations in aluminum content from 23.5 to 36.0wt%(40–55at%) had little effect on the oxidation properties. Initial experiments at 1500°C with a novel Rh marker indicate that alumina grows at least partially by outward cation diffusion both with and without Y.

In situ Raman spectroscopy study on the effect of antioxidants on high temperature oxidation properties of TMPTO

2019 ◽  
Vol 71 (5) ◽  
pp. 706-711 ◽  
Author(s):  
Bingxue Cheng ◽  
Haitao Duan ◽  
Yongliang Jin ◽  
Lei Wei ◽  
Jia Dan ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
High Temperature ◽  
Thermal Oxidation ◽  
High Temperature Oxidation ◽  
Isothermal Oxidation ◽  
In Situ Raman Spectroscopy ◽  
Temperature Oxidation ◽  
Content Type ◽  
Structure Changes ◽  
Oxidation Properties

Purpose This paper aims to investigate the thermal oxidation characteristics of the unsaturated bonds (C=C) of trimethylolpropane trioleate (TMPTO) and to reveal the high temperature oxidation decay mechanism of unsaturated esters and the nature of the anti-oxidation properties of the additives. Design/methodology/approach Using a DXR laser microscopic Raman spectrometer and Linkam FTIR600 temperature control platform, the isothermal oxidation experiments of TMPTO with or without 1.0 wt. % of different antioxidants were performed. Findings The results indicated that the Raman peaks of =C-H, C=C and -CH2- weaken gradually with prolonged oxidation time, and the corresponding Raman intensities drop rapidly at higher temperatures. The aromatic amine antioxidant can decrease the attenuation of peak intensity, as it significantly reduces the rate constant of C=C thermal oxidation. The hindered phenolic antioxidant has a protective effect during the early stages of oxidation (induction period), but it may accelerate the oxidation of C=C afterwards. Originality/value Research on the structure changes of synthetic esters during oxidation by Raman spectroscopy will be of great importance in promoting the use of Raman spectroscopy to analyze the oxidation of lubricants.

scholarly journals Additively Manufactured NiTi and NiTiHf Alloys: Estimating Service Life in High-Temperature Oxidation

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2104 ◽  
Author(s):  
Hediyeh Dabbaghi ◽  
Keyvan Safaei ◽  
Mohammadreza Nematollahi ◽  
Parisa Bayati ◽  
Mohammad Elahinia
Keyword(s):  
High Temperature ◽  
Oxidation Rate ◽  
High Temperature Oxidation ◽  
Oxidation Behavior ◽  
Early Stage ◽  
Niti Alloy ◽  
Temperature Oxidation ◽  
X Ray ◽  
Rate Law ◽  
Parabolic Rate

In this study, the effect of the addition of Hf on the oxidation behavior of NiTi alloy, which was processed using additive manufacturing and casting, is studied. Thermogravimetric analyses (TGA) were performed at the temperature of 500, 800, and 900 °C to assess the isothermal and dynamic oxidation behavior of the Ni50.4Ti29.6Hf20 at.% alloys for 75 h in dry air. After oxidation, X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy were used to analyze the oxide scale formed on the surface of the samples during the high-temperature oxidation. Two stages of oxidation were observed for the NiTiHf samples, an increasing oxidation rate during the early stage of oxidation followed by a lower oxidation rate after approximately 10 h. The isothermal oxidation curves were well matched with a logarithmic rate law in the initial stage and then by parabolic rate law for the next stage. The formation of multi-layered oxide was observed for NiTiHf, which consists of Ti oxide, Hf oxide, and NiTiO3. For the binary alloys, results show that by increasing the temperature, the oxidation rate increased significantly and fitted with parabolic rate law. Activation energy of 175.25 kJ/mol for additively manufactured (AM) NiTi and 60.634 kJ/mol for AM NiTiHf was obtained.

scholarly journals Manufacturing And High Temperature Oxidation Properties Of Electro-Sprayed Fe-24.5% Cr-5%Al Powder Porous Metal

2015 ◽  
Vol 60 (2) ◽  
pp. 1169-1173
Author(s):  
Kee-Ahn Lee ◽  
Jae-Sung Oh ◽  
Young-Min Kong ◽  
Byoung-Kee Kim
Keyword(s):  
High Temperature ◽  
High Temperature Oxidation ◽  
Porous Metal ◽  
Porous Metals ◽  
Temperature Oxidation ◽  
Spray Process ◽  
Surface Areas ◽  
Thermal Gravimetry ◽  
Oxidation Properties ◽  
Al Powder

Abstract Fe-Cr-Al based Powder porous metals were manufactured using a new electro-spray process, and the microstructures and high-temperature oxidation properties were examined. The porous materials were obtained at different sintering temperatures (1350°C, 1400°C, 1450°C, and 1500°)C and with different pore sizes (500 μm, 450 μm, and 200 μm). High-temperature oxidation experiments (TGA, Thermal Gravimetry Analysis) were conducted for 24 hours at 1000°C in a 79% N2+ 21% O2, 100 mL/min. atmosphere. The Fe-Cr-Al powder porous metals manufactured through the electro-spray process showed more-excellent oxidation resistance as sintering temperature and pore size increased. In addition, the fact that the densities and surface areas of the abovementioned powder porous metals had the largest effects on the metal’s oxidation properties could be identified.

High Temperature Oxidation Behavior of NiAl and Ni3Al Argon Arc Claddings

2011 ◽  
Vol 189-193 ◽  
pp. 441-446
Author(s):  
Xiao Xia Tan ◽  
Zong De Liu
Keyword(s):  
High Temperature ◽  
High Temperature Oxidation ◽  
Steel Substrate ◽  
Temperature Oxidation ◽  
Metallurgical Bonding ◽  
The Matrix ◽  
Oxidation Properties ◽  
High Temperature Oxidation Behavior ◽  
16Mn Steel

NiAl and Ni3Al intermetallic compound claddings are prepared by argon arc cladding technology on the 16Mn steel substrate. These claddings were oxidized for 100 hours at 850 and the oxide quality of each sample was recorded every 10 hours. The results show that the NiAl and Ni3Al claddings have homogeneous structure and few defects, and form excellent metallurgical bonding with the matrix. The oxidation kinetics results show that, the oxidation weight gain rate of NiAl was more stable than Ni3Al and tended to zero earlier. Oxide layer spallation of Ni3Al cladding was more serious than that of NiAl cladding. Thus, NiAl argon arc cladding has the more excellent high temperature oxidation properties than Ni3Al argon arc cladding.

High-temperature Oxidation Properties of Vertical Cracked TBC

2004 ◽  
Vol 2004 (0) ◽  
pp. 213-214
Author(s):  
Masayuki ARAI ◽  
Uichi IWATA ◽  
Tatsuo SUIDZU ◽  
Kazumi TANI
Keyword(s):  
High Temperature ◽  
High Temperature Oxidation ◽  
Temperature Oxidation ◽  
Oxidation Properties
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