Oxidation Resistance of Al-Rich Aluminide Coating on TiAl Based Alloy by Thermal Spray and Diffusion Treatment

Al-rich aluminide coating on Ti-49.1at%Al alloys has been performed by two-step process of thermal aluminum spray and diffusion treatment. Effect of the diffusion time on the oxidation resistance, and the change of microstructures in the coating during the oxidation test in air at 900°C for 100 h were investigated. In the aluminized coating before the oxidation tests, formations of TiAl3 on the outer layer and an intermediate layer consisting of Ti2Al5, TiAl2, and Al-rich TiAl were observed. The intermediate layer developed by the diffusion treatment for 3600s. In the oxidation test over 50 h, the specimen diffusion treated for 3600 s exhibited the lower oxidation rate than that diffusion treated for 900 s. Multi-oxide scales of TiO2 and Al2O3 were observed on the both surfaces of aluminized specimens. Large TiO2 particles were observed on the specimen of tD = 900 s. It was found that the TiAl2 layer developed during the oxidized specimen, while the thicknesses of Al-rich TiAl and TiAl3 layer decreased by the growth of TiAl2.

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Aluminizing of TiAl-Based Alloy Using Thermal Spray Coating

Materials Science Forum ◽

10.4028/www.scientific.net/msf.654-656.1884 ◽

2010 ◽

Vol 654-656 ◽

pp. 1884-1887 ◽

Cited By ~ 3

Author(s):

Tomohiro Sasaki ◽

Takahiro Yagi ◽

Takehiko Watanabe

Keyword(s):

Oxidation Resistance ◽

Intermediate Layer ◽

Pure Aluminum ◽

Spray Coating ◽

Thermal Spray Coating ◽

Diffusion Time ◽

Outermost Layer ◽

Good Oxidation Resistance ◽

Diffusion Treatment ◽

Outermost Surface

Aluminizing the surface of a TiAl-based alloy (49.1 at% Al) was carried out by thermally spraying a pure aluminum coating and subsequent diffusion treatment at 1100°C. The influence of the diffusion time for the formation of Ti-Al intermetallic phases in the coating layers and the oxidation resistance of the aluminized TiAl-based alloys were investigated. The layer formed on the outermost surface was comprised of the Al-rich intermetallic T2iAl5 and contained pores. On the other hand, an intermediate layer consisting of TiAl2 and TiAl was formed between the outermost layer and the substrate. The thickness of the outermost layer decreased as the diffusion time increased, while the thickness of the intermediate layer increased. In addition, the coating/substrate interface changed from a wavy to a linear form with the growth of the intermediate layer. The aluminized coating showed good oxidation resistance at 900°C for all diffusion times.

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Effect of Cr and Al alloying on the oxidation resistance of a Ti5Si3-incorporated MoSiBTiC alloy

High Temperature Materials and Processes ◽

10.1515/htmp-2021-0024 ◽

2021 ◽

Vol 40 (1) ◽

pp. 204-213

Author(s):

Xi Nan ◽

Tomotaka Hatakeyama ◽

Shuntaro Ida ◽

Nobuaki Sekido ◽

Kyosuke Yoshimi

Keyword(s):

Solid Solution ◽

Oxide Scale ◽

Oxidation Resistance ◽

Oxidation Behavior ◽

Oxide Scales ◽

Accelerated Oxidation ◽

Oxidation Test ◽

Poor Oxidation Resistance

Abstract The effects of adding Cr and Al on the oxidation behavior of a Ti5Si3-incorporated MoSiBTiC alloy (46Mo–28Ti–14Si–6C–6B, at%) were investigated at 800 and 1,100°C. The addition of Cr and Al largely improved the oxidation resistance of the MoSiBTiC alloy at 800°C due to the formation of Cr2(MoO4)3 and Al2(MoO4)3 in the oxide scales. These protective molybdates mainly formed on the molybdenum solid solution (Moss) and Mo3Si phases that show poor oxidation resistance in the Cr- and Al-free alloy and consequently increased the oxidation resistance of the alloys. However, accelerated oxidation occurred on the 10Al alloy after the long-term oxidation test, suggesting that the formed oxide scale has limited protection ability. At 1,100°C, the addition of Cr and Al also enhanced the oxidation resistance to some extent by forming Cr2O3 and Al2O3 in the oxide scales.

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The Influence of the Chemical Composition of Superalloys on the Oxidation Resistance of Aluminide Coating

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.227.365 ◽

2015 ◽

Vol 227 ◽

pp. 365-368

Author(s):

Maryana Zagula-Yavorska ◽

Jan Sieniawski ◽

Ryszard Filip

Keyword(s):

Chemical Composition ◽

Oxidation Resistance ◽

Aluminide Coating ◽

Inconel 625 ◽

Test Duration ◽

Oxidation Test ◽

Air Atmosphere ◽

Aluminide Coatings ◽

High Aluminum Content ◽

High Aluminum

The aim of the present work was to determine the influence of chemical composition of the coating protected nickel based superalloys Inconel 713 LC, Inconel 625 and CMSX 4 on the oxidation resistance of aluminide coating. Protective aluminide coatings were deposited in the CVD process. The low activity aluminizing at the presence of AlCl3 and H2 was carried out. Cyclic oxidation test for both coated and uncoated superalloys was performed at 1100°C for 1000 h in the air atmosphere. Microstructure of aluminide coatings after oxidation test was investigated by a scanning electron microscopy (SEM) and an energy dispersive spectroscopy (EDS). The best oxidation resistance shows uncoated Inconel 713 LC superalloy. That is due to a relatively high aluminum content in this alloy. The aluminide coating deposited on the surface of Inconel 625 shows the largest oxidation resistance (insignificnt changes of mass for the whole test duration). Excellent oxidation resistance is a result of Al2O3 scale formation.

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Meridional Circulation, Turbulence, and Diffusion Processes in Stars

International Astronomical Union Colloquium ◽

10.1017/s0252921100080477 ◽

1976 ◽

Vol 32 ◽

pp. 109-116 ◽

Cited By ~ 1

Author(s):

S. Vauclair

Keyword(s):

Convection Zone ◽

Diffusion Processes ◽

Meridional Circulation ◽

Diffusion Time ◽

Work In Progress ◽

First Results ◽

Stellar Envelopes ◽

And Diffusion ◽

Turbulence And Diffusion ◽

Hr Diagram

This paper gives the first results of a work in progress, in collaboration with G. Michaud and G. Vauclair. It is a first attempt to compute the effects of meridional circulation and turbulence on diffusion processes in stellar envelopes. Computations have been made for a 2 Mʘstar, which lies in the Am - δ Scuti region of the HR diagram.Let us recall that in Am stars diffusion cannot occur between the two outer convection zones, contrary to what was assumed by Watson (1970, 1971) and Smith (1971), since they are linked by overshooting (Latour, 1972; Toomre et al., 1975). But diffusion may occur at the bottom of the second convection zone. According to Vauclair et al. (1974), the second convection zone, due to He II ionization, disappears after a time equal to the helium diffusion time, and then diffusion may happen at the bottom of the first convection zone, so that the arguments by Watson and Smith are preserved.

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The Heat and Diffusion Treatment of Natural and Synthetic Sapphires

The Journal of Gemmology ◽

10.15506/jog.1981.17.8.528 ◽

1981 ◽

Vol 17 (8) ◽

pp. 528-541 ◽

Cited By ~ 9

Author(s):

Robert Crowningshield ◽

Kurt Nassau

Keyword(s):

Diffusion Treatment ◽

And Diffusion ◽

Natural And Synthetic

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Effects of diffusion temperature and diffusion time on fabrication of Na-diffused p-type ZnO thin films

Materials Letters ◽

10.1016/j.matlet.2012.04.092 ◽

2012 ◽

Vol 80 ◽

pp. 175-177 ◽

Cited By ~ 5

Author(s):

Huibin Liu ◽

Xinhua Pan ◽

Ping Ding ◽

Zhizhen Ye ◽

Haiping He ◽

...

Keyword(s):

Thin Films ◽

Diffusion Time ◽

Zno Thin Films ◽

Diffusion Temperature ◽

P Type ◽

And Diffusion

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Confinement and diffusion time-scales of CR hadrons in AGN-inflated bubbles

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stx1404 ◽

2017 ◽

Vol 470 (3) ◽

pp. 3388-3394 ◽

Cited By ~ 3

Author(s):

D. A. Prokhorov ◽

E. M. Churazov

Keyword(s):

Time Scales ◽

Diffusion Time ◽

And Diffusion

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Research on Thermal Spray Al-Al2O3/TiO2 Coating and Diffusion Treatment on Magnesium Alloy

Materials Science Forum - Advances in Materials Manufacturing Science and Technology II ◽

10.4028/0-87849-421-9.217 ◽

2006 ◽

pp. 217-220

Author(s):

Hong Ye ◽

Zhong Lin Yan ◽

Zhi Fu Sun ◽

Ying Wang

Keyword(s):

Magnesium Alloy ◽

Thermal Spray ◽

Diffusion Treatment ◽

And Diffusion

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The Distribution Trend of Boron Atoms in Semiconductor Silicon under High Temperature

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.871.243 ◽

2021 ◽

Vol 871 ◽

pp. 243-247

Author(s):

Zhi Huan Zhao ◽

Zhi Bin Zhao ◽

Ming Ming Jiang ◽

Chuan Zhong Chen ◽

Wei Hai Song ◽

...

Keyword(s):

Geometric Model ◽

Impurity Distribution ◽

Diffusion Time ◽

Internal Dynamic ◽

Diffusion Test ◽

Hydrodynamic Parameters ◽

Whole Process ◽

Diffusion Temperature ◽

The Relationship ◽

And Diffusion

The ProENGINEER software is used to build a geometric model for the whole process cavity and internal structure and conduct the internal dynamic simulation of cavity with different diffusion temperatures of 1,000°C, 1,050°C, 1,100°C and 1,150°C, and different diffusion time of 5 min, 10 min, 15 min and 20 min. Analyze the process control indexes by combining with specific thermal diffusion test, and study the relationship between hydrodynamic parameters and diffusion uniformity, Comprehensively investigate the effects of the diffusion temperature and diffusion time on doping, achieving the requirements of impurity distribution in materials.

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