scholarly journals Improve oxidation resistance at high temperature by nanocrystalline surface layer

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Z. X. Xia ◽  
C. Zhang ◽  
X. F. Huang ◽  
W. B. Liu ◽  
Z. G. Yang
2021 ◽  
Vol 40 (1) ◽  
pp. 397-409
Author(s):  
Ziliu Xiong ◽  
Zhangguo Lin ◽  
Jianjun Qi ◽  
Li Sun ◽  
Guangxin Wu ◽  
...  

Abstract High-temperature oxidation resistance, hot formability, element distribution, and microstructure of Al-10% Si-(0.5–3.0%)Cu coating were investigated by means of glow discharge spectroscopy, optical microscope, scanning electron microscope, and energy-dispersive spectroscopy. Results show that the addition of Cu can increase high-temperature oxidation resistance above 950°C and improve hot formability so that no crack spreads into substrate steel as hot forming at 33.3% strain. Oxidation film structure is continual and compacting, and Si highly concentrates in the surface layer. The distribution of Cu has skin effect with peaking content 8.2% in the surface layer. After hot stamping, Al and Si diffuse into substrate steel, and Cu diffuses from inner to outer coating. Al–Si–Cu coating has smoother surface, straighter diffusion layer, and finer metal compound than Al–Si coating. Surface and diffusion layers are identified as aluminum oxide, Si-rich, and Cu phase and Al7SiFe2, Al3Fe, and CuAl3, respectively. Al-rich phase and the metal compound are composed of α-Al dissolving Fe, Si, and Cu and Al–Si matrix, Cu3Al, respectively.


2015 ◽  
Vol 1760 ◽  
Author(s):  
Takahiko Ito ◽  
Shogo Ikeda ◽  
Katsushi Tanaka

ABSTRACTOxidation tests of Cr containing Co-based superalloys with compositions of Co-20at.%Ni-9at.%Al-9at.%W-x at.%Cr (x = 2, 4, 6, 8 and 10) have been carried out at 1173 and 1273 K in air. Oxidation resistance is improved upon alloying with Cr not only at 1173 K but also at 1273 K. The weight gain of the 10at.%Cr alloy oxidized at 1173 K is similar to that of the 5th generation Ni-based superalloy of TMS-173. Alloying with Cr is efficient to improve oxidation resistance, however, the shape of γ’ precipitates is rounded and the alignment of the precipitates along the <100> direction becomes less pronounced upon alloying with Cr.


Author(s):  
H. Kung ◽  
T. R. Jervis ◽  
J.-P. Hirvonen ◽  
M. Nastasi ◽  
T. E. Mitchell ◽  
...  

MoSi2 is a potential matrix material for high temperature structural composites due to its high melting temperature and good oxidation resistance at elevated temperatures. The two major drawbacksfor structural applications are inadequate high temperature strength and poor low temperature ductility. The search for appropriate composite additions has been the focus of extensive investigations in recent years. The addition of SiC in a nanolayered configuration was shown to exhibit superior oxidation resistance and significant hardness increase through annealing at 500°C. One potential application of MoSi2- SiC multilayers is for high temperature coatings, where structural stability ofthe layering is of major concern. In this study, we have systematically investigated both the evolution of phases and the stability of layers by varying the heat treating conditions.Alternating layers of MoSi2 and SiC were synthesized by DC-magnetron and rf-diode sputtering respectively. Cross-sectional transmission electron microscopy (XTEM) was used to examine three distinct reactions in the specimens when exposed to different annealing conditions: crystallization and phase transformation of MoSi2, crystallization of SiC, and spheroidization of the layer structures.


Alloy Digest ◽  
2004 ◽  
Vol 53 (12) ◽  

Abstract Udimet L-605 is a high-temperature aerospace alloy with excellent strength and oxidation resistance. It is used in applications such as gas turbine blades and combustion area parts. This datasheet provides information on composition, physical properties, and tensile properties as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, and joining. Filing Code: CO-109. Producer or source: Special Metals Corporation.


Alloy Digest ◽  
2013 ◽  
Vol 62 (4) ◽  

Abstract NAS HX (UNS N06002) is a nickel-chromium-iron-molybdenum alloy with outstanding strength and oxidation resistance. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance as well as forming, heat treating, and joining. Filing Code: Ni-707. Producer or source: Nippon Yakin Kogyo Company Ltd.


Alloy Digest ◽  
2005 ◽  
Vol 54 (11) ◽  

Abstract Incotherm TD is a thermocouple-sheathing alloy with elements of silicon and rare earths to enhance oxidation resistance at high temperatures. This datasheet provides information on composition, physical properties, and tensile properties as well as deformation. It also includes information on high temperature performance and corrosion resistance as well as forming. Filing Code: Ni-628. Producer or source: Special Metals Corporation.


Alloy Digest ◽  
1954 ◽  
Vol 3 (12) ◽  

Abstract HASTELLOY Alloy X is a nickel-chromium-iron-molybdenum alloy recommended for high-temperature applications. It has outstanding oxidation resistance at high temperatures under most operating conditions, and good high-temperature strength. This datasheet provides information on composition, physical properties, and tensile properties as well as creep. It also includes information on forming, heat treating, and machining. Filing Code: Ni-14. Producer or source: Haynes Stellite Company.


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