TEM characterization of reaction zone in a SiC fiber-reinforced titanium alloy

1988 ◽  
Vol 46 ◽  
pp. 738-739
Author(s):  
G. Das ◽  
R. E. Omlor
Keyword(s):  
Titanium Alloys ◽  
Reaction Zone ◽  
Carbon Layer ◽  
Fiber Reinforced ◽  
Reaction Products ◽  
Sic Fibers ◽  
Sic Fiber ◽  
The Matrix ◽  
Immense Potential

Fiber reinforced titanium alloys hold immense potential for applications in the aerospace industry. However, chemical reaction between the fibers and the titanium alloys at fabrication temperatures leads to the formation of brittle reaction products which limits their development. In the present study, coated SiC fibers have been used to evaluate the effects of surface coating on the reaction zone in the SiC/IMI829 system.IMI829 (Ti-5.5A1-3.5Sn-3.0Zr-0.3Mo-1Nb-0.3Si), a near alpha alloy, in the form of PREP powder (-35 mesh), was used a茸 the matrix. CVD grown AVCO SCS-6 SiC fibers were used as discontinuous reinforcements. These fibers of 142μm diameter contained an overlayer with high Si/C ratio on top of an amorphous carbon layer, the thickness of the coating being ∽ 1μm. SCS-6 fibers, broken into ∽ 2mm lengths, were mixed with IMI829 powder (representing < 0.1vol%) and the mixture was consolidated by HIP'ing at 871°C/0. 28GPa/4h.

Role of matrix microstructure in the ultrasonic characterization of fiber-reinforced metal matrix composites

1997 ◽  
Vol 12 (3) ◽  
pp. 754-763 ◽  
Author(s):  
S. Krishnamurthy ◽  
T. E. Matikas ◽  
P. Karpur
Keyword(s):  
Titanium Alloy ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Matrix Composites ◽  
Fiber Reinforced ◽  
Matrix Microstructure ◽  
Sic Fiber ◽  
The Matrix ◽  
Ultrasonic Images

This work deals with the application of ultrasonic nondestructive evaluation for characterizing fiber-reinforced metal matrix composites. The method involved the use of a recently developed technique in which the fiber reinforcement acts as a reflector to incident ultrasonic shear waves. Single fiber and multifiber, single ply composites consisting of SiC fibers in several titanium alloy matrices were investigated. The ultrasonic images obtained were correlated with the results of metallographic characterization of the composites. The results showed that the ultrasonic response of the metal matrix composites is significantly influenced by the microstructure of the matrix through which the incident wave traverses. The general effects of matrix on ultrasonic wave propagation are reviewed, and the ultrasonic signals obtained from various SiC fiber-reinforced titanium alloy composites are discussed in terms of the scattering effects of matrix microstructure.

Reinforcement/Matrix Interaction in Sic Fiber-Reinforced Ni3a1 Matrix Composites

1988 ◽  
Vol 133 ◽  
Author(s):  
J.-M. Yang ◽  
W. H. Kao ◽  
C. T. Liu
Keyword(s):  
Reaction Zone ◽  
Nickel Aluminide ◽  
Chemical Compositions ◽  
Matrix Composites ◽  
Reaction Products ◽  
Sic Fiber ◽  
Barrier Coating ◽  
Reaction Characteristics ◽  
Different Types ◽  
The Matrix

ABSTRACTThe interfacial reaction characteristics of two different types of SiC fibers with Ni3A1 (Ni-Al-Cr-Zr-B) matrix have been investigated. The microstructure and chemical compositions across the reaction zone have been analyzed quantitatively using microscopy and electron probe microanalysis. In both types of SiC/Ni3Al composites, it was found that Ni was the dominant diffusing species responsible for the overall reaction. The C-rich layer outside the SCS-6 fiber provided an incubation period, but could not stop the inward diffusion of Ni. It could, however, effectively stop the diffusion of Al, Zr and Cr. No significant increase in reaction zone thickness after exposure at temperatures below 900 °C for up to 100 hours was observed. When the C-rich layer was depleted, a rapid increase in reaction zone thickness and the formation of multilayer reaction products occurred. In the case of Sigma/Ni3A1 composite, extensive reaction between the fiber and the matrix occurred at all the temperatures studied. Diffusion barrier coating for both types of fibers is required to develop nickel aluminide matrix composites.

scholarly journals Effects of Defects on Bond Behavior of Fiber Reinforced Cementitious Matrix Materials

Materials ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 164 ◽  
Author(s):  
Antonio Bilotta ◽  
Gian Piero Lignola
Keyword(s):  
High Strength ◽  
Epoxy Adhesive ◽  
Fiber Reinforced ◽  
Bond Behavior ◽  
The Matrix ◽  
Low Sensitivity ◽  
Strengthening Technique ◽  
Geometrical Defects ◽  
Bond Tests

High-strength fibers embedded in inorganic matrix i.e., Fiber Reinforced Cementitious Mortar materials (FRCM) are commonly used as strengthening technique for existing masonry structures, due to the low sensitivity to debonding phenomena between substrate and matrix. Nevertheless, the use of lime or cement-based matrix instead of epoxy adhesive implies that attention has to be paid to the bond behavior between the fibers and the matrix, since sliding phenomena and cohesive failures in the mortar matrix can occur. The paper aims to investigate the effect of the mechanical properties of fiber and matrix on the FRCM efficiency, and potential geometrical defects, typical of real applications. The aim is to analyze the mechanical behavior of the FRCM system by simulating hypothetical bond tests, as they are usually performed in laboratories. The bond test has a significant role, as it is used for the qualification of the material, providing sometimes very scattered results. Hence, it is particularly important and greatly discussed in the scientific community and among manufactures and practitioners. The purpose is to understand where this variability could derive from and possibly how to contain it, to improve the characterization of FRCM systems. A mechanical model has been proposed to simulate the usual bond test to focus and stress the way in which each fiber slips out of the matrix as the load increases; and this has been recognized as the main reason for scattered results in bond tests. The model was then applied to the typical cases of PBO-FRCM and Glass-FRCM, hence considering different ratios for the fiber and matrix properties.

The characterization of an SCS6/Ti–6Al–4V MMC interphase

1989 ◽  
Vol 4 (2) ◽  
pp. 327-335 ◽  
Author(s):  
C. Jones ◽  
C. J. Kiely ◽  
S. S. Wang
Keyword(s):  
Metal Matrix ◽  
Chemical Interaction ◽  
Auger Spectroscopy ◽  
Carbon Layer ◽  
Convergent Beam Electron Diffraction ◽  
Interphase Region ◽  
The Matrix ◽  
Convergent Beam

Using TEM, Auger spectroscopy, EDX, and convergent beam electron diffraction, a thorough characterization of the interphase region between SCS6 fibers and Ti–6Al–4V matrix in a metal matrix composite has been performed. The interphase region is shown to be very complex, consisting of numerous layers of varying compositions and thicknesses. The chemical interaction of the fiber and matrix results in a 0.5–1.5 μm thick TiC layer. Evidence for the existence of a Tix Siy (C) layer is also presented. The SCS6 overlayer on the fibers has inhibited any chemical interaction between the matrix and the SiC filament itself, 60% of the interphase region originating from the SCS6 protective coating. In situ fracture experiments (in an Auger spectrometer) reveal that fracture takes place between the TiC and an amorphous carbon layer.

Diffusion barrier development for fiber-reinforced Ni3Al composites

1991 ◽  
Vol 6 (2) ◽  
pp. 355-360 ◽  
Author(s):  
P.C. Brennan ◽  
W.H. Kao ◽  
H.A. Katzman ◽  
J-M. Yang
Keyword(s):  
Diffusion Barrier ◽  
Nickel Aluminide ◽  
Chemical Vapor ◽  
Chemical Compositions ◽  
Ion Microprobe ◽  
Fiber Reinforced ◽  
Reaction Products ◽  
Barrier Coating ◽  
Before And After ◽  
The Matrix

An alumina (Al2O3) diffusion barrier coating to inhibit the interfacial reactions between boron-carbide-coated boron (B4C/B) fibers and a nickel-aluminide (Ni3Al) (IC-221) matrix was investigated. The alumina diffusion barrier was deposited on the B4C/B fibers using chemical vapor deposition. Also, Saphikon single-crystal Al2O3 fibers were used to demonstrate the compatibility between Al2O3 and Ni3Al. The detailed microstructures and chemical compositions of the fibers, coating, and matrix before and after various thermal exposures were analyzed using scanning electron microscopy, energy dispersive x-ray analysis, and ion microprobe mass analysis. The interfacial reaction products present after 6 h at 980 °C were characterized, and Ni was found to be the dominant diffusion species. The alumina diffusion barrier shows promise for effectively inhibiting the deleterious reactions between B4C/B fibers and the Ni3Al matrix. The uncoated B4C/B fibers were consumed by the matrix after fabrication alone, whereas the Al2O3 coated fibers demonstrated resistance to the matrix for 25 h at 880 °C and 6 h at 980 °C. The Saphikon fiber-reinforced Ni3Al composites demonstrated excellent compatibility after 50 h at 1000 °C. Zirconium (Zr)-rich precipitates on the order of 2 μm in diameter formed at the fiber interface after this exposure, but no gross reaction was indicated between the fiber and the matrix.

The Flexural Strength of Glass Fiber Reinforced Polyester Filled with Aluminum Tri-Hydroxide and Montmorillonite

2018 ◽  
Vol 772 ◽  
pp. 28-32 ◽  
Author(s):  
Sunarto Kaleg ◽  
Dody Ariawan ◽  
Kuncoro Diharjo
Keyword(s):  
Elastic Modulus ◽  
Flexural Strength ◽  
Glass Fiber ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Gfrp Composite ◽  
The Matrix

Aluminum tri-hydroxide (ATH) and montmorillonite (MMT) are capable to enhance flame retardancy of glass fiber reinforced polymer (GFRP). Nevertheless, the combination of both flame retardant fillers on changes in the mechanical properties of GFRP is not yet known. The characterization of flexural strength and scanning electron microscope (SEM) observation on GFRP composite has been done. The result of flexural properties testing shows that the addition of ATH or MMT or a combination of both on the GFRP causes a decrease in flexural strength. GFRP with increased ATH loading causes an increase in elastic modulus. Contrarily, the MMT addition causes a decrease in the elastic modulus of the GFRP composite. SEM results on the fractured samples show that the high content of ATH or MMT in the UP tends to agglomerate thus showing visible holes that were formed from the filler particles pulled out from the matrix.

Interfacial characterization of a SiC fiber-reinforced AlN composite

1995 ◽  
Vol 32 (1) ◽  
pp. 121-126
Author(s):  
K. Park ◽  
T. Vasilos ◽  
C. Sung
Keyword(s):  
Fiber Reinforced ◽  
Sic Fiber
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