Characterization of Fiber/Matrix Interfaces by Transmission Electron Microscopy in Titanium Aluminide/Sic Composites

1992 ◽  
Vol 273 ◽  
Author(s):  
Cecil G. Rhodes
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Titanium Aluminide ◽  
Matrix Composition ◽  
Matrix Composites ◽  
Reaction Products ◽  
Alloy Matrix ◽  
Transmission Electron ◽  
Matrix Reinforcement ◽  
Sic Composites

ABSTRACTThis paper presents examples of the use of transmission electron microscopy to characterize matrix/reinforcement interaction in titanium aluminide matrix composites reinforced with continuous SCS-6 type SiC. As a result of the high temperature required for consolidating this type composite, reaction products form in the interface. Using diffraction and x-ray energy dispersive spectroscopy techniques, reaction products in Ti3Al and Ti2AINb alloy matrix composites have been identified. TiC1 –x and Ti5 Si3 compounds are common in these composites, with AlTi3C also present depending on consolidation temperature and matrix composition. Residual stress calculations indicate that these reaction products may be subject to cracking during cooling from consolidationtemperatures.

Fibre-Matrix Reaction Zones in Model Silicon Carbide-Titanium Aluminide Metal-Matrix Composites

1989 ◽  
Vol 170 ◽  
Author(s):  
D. R. Baker ◽  
P. J. Doorbar ◽  
M. H. Loretto
Keyword(s):  
Electron Microscopy ◽  
Titanium Aluminide ◽  
Chemical Information ◽  
Matrix Composites ◽  
Reaction Products ◽  
Transmission Electron ◽  
Complex Carbides ◽  
Reaction Zones ◽  
Electron Energy Loss ◽  
Fibre Matrix

AbstractThe reactions between coated SiC continuous fibres and TiAl, Ti3A1, or Ti3A1 + β matrices, have been investigated using optical metallography, scanning electron microscopy (SEM), and transmission electron microscopy (TEM), with chemical information obtained by energy dispersive x-ray analysis (EDX) and electron energy loss spectroscopy (EELS).Similar sequences of phases were found in all the composites; carbides based on TiC and TixAIC (x=2,3) and titanium silicides based on Ti5Si3 forming in narrow bands outside of the complex carbides. The occurrence of individual phases can be related to published phase diagram information. However, the sequences in which the reaction products occur within the reaction zones cannot be fully rationalised from the present results.

Interfacial Reactions in Metal-Matrix Composites

1995 ◽  
Vol 398 ◽  
Author(s):  
J. R. Heffelfinger ◽  
R. R. Kieschke ◽  
C. B. Carter
Keyword(s):  
Electron Microscopy ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Ti Alloy ◽  
Matrix Composites ◽  
Reaction Products ◽  
Alloy Matrix ◽  
Β Phase ◽  
Transmission Electron ◽  
The Matrix

ABSTRACTThe interfacial reaction between Al2O3 (alumina) and a β-Ti alloy has been characterized by transmission electron microscopy, scanning electron microscopy, and X-ray energy-dispersive spectroscopy. Diffusion bonding single-crystal alumina and a β-Ti alloy was found to produce three interfacial regions: a region of intermetallics (Tl3Al and TiAl) located near the alumina interface, an α-Ti region, and a β-Ti region (rich in Mo, the β-phase stabilizer). Of the intermetallics to form, Ti3Al was found to form first and have an aligned, planar interface with the alumina. TiAl formed second and was found to separate grains of Ti3Al and the alumina. Reaction products observed in the diffusion-bonded alumina/β-Ti couples are compared with those observed in metal-matrix composites (MMCs), where a β-Ti alloy matrix is reinforced with alumina fibers. Different coatings used in MMCs are investigated for their ability to prevent the reaction between the matrix and fibers.

Microtexture of shock reaction products of niobium and silica mixtures

1999 ◽  
Vol 14 (7) ◽  
pp. 3169-3174 ◽  
Author(s):  
Reiko Murao ◽  
Masae Kikuchi ◽  
Kiyoto Fukuoka ◽  
Eiji Aoyagi ◽  
Toshiyuki Atou ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Shock Compression ◽  
Pressure Range ◽  
Reaction Products ◽  
Small Particles ◽  
Powder Mixtures ◽  
X Ray ◽  
Transmission Electron

Shock compression experiments on powder mixtures of niobium metal and quartz were conducted for the pressure range of 30–40 GPa by a 25-mm single-stage propellant gun. Chemical reaction occurred above 35 GPa, and products were found to be mainly so-called “Cu3Au-type” Nb3Si, which contained a small amount of oxygen. Microtextures of the specimen were examined by scanning and transmission electron microscopy. A field-emission transmission electron microscope was used for energy-dispersive x-ray analysis of microtextures in small particles found in the SiO2 matrix, and various species with different Nb/Si ratio and oxygen content were shown to be produced through the nonequilibrium process of shock compression.

Electron microscopy study of interfacial structure and reaction of Yba2Cu3O7/Y-ZrO2 films on LaAlO3 substrates

1998 ◽  
Vol 13 (6) ◽  
pp. 1485-1491 ◽  
Author(s):  
J. Y. Dai ◽  
F. H. Kaatz ◽  
P. R. Markworth ◽  
D. B. Buchholz ◽  
X. Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Interfacial Reaction ◽  
Chemical Vapor ◽  
Atomic Layer ◽  
High Resolution Electron Microscopy ◽  
Microscopy Study ◽  
Interfacial Structure ◽  
Reaction Products ◽  
Transmission Electron

The detailed structure and interfacial reaction of epitaxial Yba2Cu3O7/Y-ZrO2 (YBCO/YSZ) films grown by chemical vapor deposition (CVD) on LaAlO3 (LAO) substrates are investigated by means of high-resolution electron microscopy (HREM), analytical transmission electron microscopy, and scanning transmission electron microscopy (STEM). The epitaxial relations of YBCO/YSZ/LAO are [100]YBCO // [110]YSZ // [100]LAO and (001)YBCO // (001)YSZ // (001)LAO. The optimum atomic configuration at the YSZ/LAO interface, in which oxygen is the first atomic layer on LAO, is proposed by using HREM combined with image simulation based on the atomic structure models of the interface. Near the YBCO/YSZ interface, two localized interfacial reaction products are formed: (i) a Y-rich modulated ZrO2 structure at the surface of the YSZ film, which may be caused by the diffusion of Y into the YSZ grains; (ii) an intergranular BaZrO3 phase formed by the diffusion of Ba along the columnar grain boundaries of the YSZ film during YBCO growth.

A Study of Fibre/Matrix Interfaces in TiAl/Sic Composites

1994 ◽  
Vol 364 ◽  
Author(s):  
S. Djanarthany ◽  
C. Servant ◽  
C. Colin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Hot Pressing ◽  
Matrix Interface ◽  
Arc Spray ◽  
Transmission Electron ◽  
Sic Composites ◽  
Fibre Matrix ◽  
Scanning Electron

AbstractA continuous fibre reinforced SiC/TiAl composite has been prepared by arc spray and hot pressing. The as-fabricated fibre/matrix interface of monotapes and composites have been examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The arc-spray conditions result in a decohesion at the fibre/matrix interface.

Chemical and Morphological Analysis of Sol-derived Kca2Nb3O10

1999 ◽  
Vol 14 (4) ◽  
pp. 1325-1328 ◽  
Author(s):  
Steven T. Kim ◽  
Vinayak P. Dravid ◽  
Sankar Sambasivan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Morphological Analysis ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Morphological Properties ◽  
Layered Perovskite ◽  
Matrix Composites ◽  
Fiber Coating ◽  
Transmission Electron

The chemical and morphological properties of a sol-derived layered perovskite compound, Kca2Nb3O10 (KCN), are presented. Development of this compound is motivated by its use as an interphase fiber-coating material for ceramic matrix composites (CMC's). In such systems, this material is to be placed between the fiber and matrix to control crack propagation in the vicinity of the fiber, thereby enhancing toughness. Comparative analyses are performed between known bulk specimens of KCN and the sol-derived product using transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). The suitability of the sol-derived KCN for CMC applications is demonstrated through microstructure and chemical composition similar to that of the known bulk KCN samples.

Alpha-Si3N4 Precipitation in C/C-SiC Composites from inherent Fiber Impurity Sources

1994 ◽  
Vol 365 ◽  
Author(s):  
Roland Pleger ◽  
Wolfgang Braue
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Transmission Electron Microscopy ◽  
Carbon Fibers ◽  
Vapor Phase ◽  
Reaction Front ◽  
Reactive Nitrogen ◽  
Transmission Electron ◽  
Silicon Vapor ◽  
Sic Composites

ABSTRACTThe formation of crystalline α-Si3N4 filaments grown inside the pore channels of HT-carbon fibers from a 2D C/C-SiC composite is investigated by transmission electron microscopy. Precipitation of α-Si3N4 is promoted by a low carbonization heat treatment of the C/C material prior to liquid silicon infiltration and results from the interaction of a highly reactive nitrogen-rich vapor phase released from the fiber and silicon vapor diffusing ahead of the SiC reaction front into the porous microtexture of the fiber.

scholarly journals Microstructure Characterization of SiC Reinforced Aluminium and Al4Cu Alloy Matrix Composites

2017 ◽  
Vol 62 (2) ◽  
pp. 747-755 ◽  
Author(s):  
B. Leszczyńska-Madej ◽  
A. Wąsik ◽  
M. Madej
Keyword(s):  
Electron Microscopy ◽  
Nitrogen Atmosphere ◽  
Powder Metallurgy Method ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
Alloy Matrix ◽  
Transmission Electron ◽  
Composite Microstructure ◽  
Xrd Techniques

AbstractA conventional powder metallurgy method (PM) was used to produce Al-SiC and Al4Cu alloy matrix composites with 2.5, 5, 7.5 and 10 wt% of SiC particles. Two different sizes of the reinforcing phase particles were applied to determine their effect on composite microstructure. The sintering process was carried out at 600°C under nitrogen atmosphere, and its consequence was the appearance of aluminium nitrides in composite microstructure acting as an additional strengthening phase. The composites were next re-pressed and re-sintered (2p2s) under the same conditions. The main aim of this article was to examine the microstructure of the SiC reinforced Al and Al4Cu alloy matrix composites. To achieve this goal and characterize the sintered materials, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) techniques were used.

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