Effect of interface reaction and diffusion on stress-oxidation coupling at high temperature

2018 ◽  
Vol 123 (15) ◽  
pp. 155301 ◽  
Author(s):  
Mengkun Yue ◽  
Xuelin Dong ◽  
Xufei Fang ◽  
Xue Feng
Keyword(s):  
High Temperature ◽  
Interface Reaction ◽  
And Diffusion ◽  
Reaction And Diffusion ◽  
Oxidation Coupling

Improving the High-Temperature Tensile Strength of SiTiC/TiAl Micro Composites by Interface Engineering

2009 ◽  
Vol 1184 ◽  
Author(s):  
Takakazu Suzuki
Keyword(s):  
High Temperature ◽  
Titanium Carbide ◽  
Interfacial Reaction ◽  
Fiber Reinforced ◽  
Cross Sectional ◽  
Interface Modification ◽  
Interface Layers ◽  
Tial Layer ◽  
And Diffusion ◽  
Reaction And Diffusion

AbstractSiC-fiber-reinforced TiAl composites (SiC/TiAl) have attractive attention due to their potential for replacing titanium and nickel-base alloys in aerospace systems such as advanced turbine engines and hypersonic vehicles where specific strength and stiffness at high temperature are critical. The interface layers of SiC/TiAl are believed to contribute strongly to its mechanical properties. A variety of interface modification, such as C, BN, W, and/or Mo coatings has been applied to the fiber to produce composites, together with the identification of several new interface modification systems, showing promise for high-performance fibers and improved composite properties. A research from a perfect cross-sectional view to get more direct and reliable interfacial information especially about bonding around the fiber circumference, has been limited partly due to the difficulty of preparing suitably thin TEM specimen without damaging the interface layers. We report our preparation method for a perfect cross-sectional TEM specimen of SiC/TiAl and the interface characterization results.Single SiC-based Si-Ti-C-O fiber (SiTiC) ˜13 μm in diameter containing about 2% Ti to improve its thermal stability has been used as a reinforcement. Chemical or physical vapor deposition has been used to deposit C or TiAl layer. C layer has been deposited-uniformly around the fiber at a thickness of about 100 nm and TiAl coating at about 1400 nm. C layer consisted of large amounts of micro crystals of about 1-30 nm accumulated around the interface of C layer and fiber. TiAl layer consisted of crystals of about 60-360nm.The specimen has been annealed at 1173 K for 2 hrs in Ar, and prepared by sandwiching and 3mm disks obtained by ultrasonic drilling and mechanical-polishing to ∼100 μm. Those disks have been further ground by a dimpler to ∼10 μm, and argon-ion-milling to get an electron-beam-transparent foil. H-9000UHR II TEM operating at 300 kV, equipped with EDX (prove 1nm) has been used.Interfacial reaction and diffusion mainly occurred in the interface between the C layer and SiTiC fiber and the C and TiAl layers. No direct reaction or diffusion occurred between the SiTiC fiber and TiAl layer. Small amounts of needle-like compound assigned as Aluminum Titanium Carbide, (Ti3AlC)5C, propagating into the fiber has been found at the interface area. These compounds consist of C, Si, O, Ti, and Al, indicating they are reaction and diffusion products of SiTiC fiber and TiAl. Such Aluminum Titanium Carbide propagating into the fiber seems to induce new stress concentration and generate new crack in the fiber and degrade the fiber and the composite strength. Combined with the tensile testing of SiTiC/TiAl single fiber reinforced composites reported previously, we surmise that the large amounts of small crystals accumulating in the C layer contribute to resistance to interfacial reaction and diffusion between the fiber and TiAl layer.

High-temperature oxidation and diffusion behaviours of YG6X and Inconel625

2019 ◽  
Vol 546 (1) ◽  
pp. 137-147
Author(s):  
Erliang Liu ◽  
Xudong Wei ◽  
Mingming Wang ◽  
Tengda Wang
Keyword(s):  
High Temperature ◽  
High Temperature Oxidation ◽  
Temperature Oxidation ◽  
And Diffusion

Solid-State Reaction and Diffusion Behaviors of CaFe2O4 and TiO2 at 1373 K to 1473 K

2021 ◽  
Author(s):  
Mingrui Yang ◽  
Junyi Xiang ◽  
Chenguang Bai ◽  
Xuangeng Zhou ◽  
Zhongci Liu ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
And Diffusion ◽  
Diffusion Behaviors ◽  
Reaction And Diffusion

Decoupling Electrochemical Reaction and Diffusion Processes in Ionically-Conductive Solids on the Nanometer Scale

ACS Nano ◽  
2010 ◽  
Vol 4 (12) ◽  
pp. 7349-7357 ◽  
Author(s):  
Nina Balke ◽  
Stephen Jesse ◽  
Yoongu Kim ◽  
Leslie Adamczyk ◽  
Ilia N. Ivanov ◽  
...  
Keyword(s):  
Diffusion Processes ◽  
Electrochemical Reaction ◽  
Nanometer Scale ◽  
And Diffusion ◽  
Reaction And Diffusion

scholarly journals Reaction-Diffusion Systems: Self-Balancing Diffusion and the Use of the Extent of Reaction as a Descriptor of Reaction Kinetics

2019 ◽  
Author(s):  
Miloslav Pekař
Keyword(s):  
Reaction Kinetics ◽  
Reaction Diffusion ◽  
Reaction Diffusion Systems ◽  
Diffusion Systems ◽  
And Diffusion ◽  
Reaction And Diffusion

Self-balancing diffusion is a concept which restricts the introduction of extents of reactions. This concept is analyzed in detail for mass- and molar-based balances of reaction-diffusion mixtures, in relation to non-self-balancing cases, and with respect to its practical consequences. A note on a recent generalization of the concept of reaction and diffusion extents is also included.<br>

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