Interface And Near-Interface Microstructure Of Discontinuous Reinforced Metal Matrix Composites

1991 ◽  
Vol 238 ◽  
Author(s):  
James P. Lucas ◽  
Nancy Y. C. Yang ◽  
John J. Stephens
Keyword(s):  
Electron Microscopy ◽  
Metal Matrix Composites ◽  
Reaction Zone ◽  
Metal Matrix ◽  
Interfacial Microstructure ◽  
Second Phase ◽  
Matrix Composites ◽  
Interface Microstructure ◽  
Matrix Microstructure ◽  
The Matrix

ABSTRACTInterfacial microstructure can have a significant influence on the microfracture processes of discontinuous reinforced metal matrix composites (DMMCs). The fracture properties, however, are largely influenced by the microfracture and deformation mechanisms associated with the matrix microstructure and with the interface microstructure. Also, it is known that the paniculate morphology and distribution can modify the deformation process by influencing the stress state that develops in the matrix materials near the reinforcement. Along with the matrix microstructure, characterizing the role of the interfacial and the near-interfacial microstructure is essential for a broader understanding of fracture behavior in DMMCs. To characterize the microstructure of cast DMMCs, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and electron microprobe (EMP) examinations were conducted at the interface and in regions near the particulate/matrix interface. Materials studied consisted of cast Al-4.5Cu and Al-7Si matrix alloy systems with B4C and SiC reinforcement. In general, the interfacial and matrix microstructure of Al-4.5Cu/SiC and Al-4.5 CuB4C composites exhibited little variance, i.e. the reinforcement type had no apparent effect on the resultant microstructures. For the Al-7Si system, however, significant microstructural variance was observed both in the matrix and interfacial regions. In the Al-7Si/B4C composite, an extensive reaction zone was found at the B4C interface. Interfacial compounds observed in Al-7SiC/B4C were Ti(O,B), Si, and MgB6 precipitates. In the near-interface region compounds such as Alx(B, C, 0)y, AlxMg(1−x)B2, and Al4C3 were found. In sharp contrast to Al-7SiC/B4C, an extensive interfacial reaction zone was not revealed for Al-7Si/SiC MMC. Only isolated, extremely fine second phase precipitates were observed on SiC paniculate interfaces. Fracture surface evidence suggested that both the matrix and the interface microstructure influenced deformation and microfracture mechanisms in DMMCs.

The role of microscopy in the development of metal matrix composites

1992 ◽  
Vol 50 (1) ◽  
pp. 162-163
Author(s):  
Gilles L'Espérance ◽  
David J. Lloyd
Keyword(s):  
Electron Microscopy ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Grain Structure ◽  
Analytical Transmission Electron Microscopy ◽  
Matrix Composites ◽  
Matrix Microstructure ◽  
Transmission Electron ◽  
The Matrix

From the very beginning of the development of metal matrix composites, (MMC's), electron microscopy has played a major role in their development. Thus, analytical transmission electron microscopy, (ATEM), has been used to characterize and study: the reinforcements in MMC's, interfacial reactions and products that can occur at the interface between the matrix and the reinforcement and the detailed matrix microstructure, particularly the dislocation and grain structure and the precipitation/constituent phases. In this presentation, we will review and discuss the contribution of ATEM to each of these points and describe how it provided necessary information in the design and use of these materials. The presentation will mainly discuss Al-based composites although work from Ti and Mg-based composites will also be presented.

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.

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.

The role of TEM in the development of advanced materials

1990 ◽  
Vol 48 (4) ◽  
pp. 176-177
Author(s):  
M H Loretto
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Advanced Materials ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
The Matrix ◽  
Scanning Electron

In general the microstructural assessment of advanced materials can be satisfactorily assessed using optical and scanning electron microscopy together with X-ray diffraction. Transmission electron microscopy (TEM) is used only when the scale and nature of the information which can be obtained from TEM is appropriate. The aim of the present article is to highlight some examples of the unique role that TEM has played in the field of structural materials. Four areas will be discussed: metal matrix composites; precipitation in Al-Li based alloys; rapid solidification; intermetallics.In the field of metal-matrix composites one of the most important aspects is nature of the bonding and interaction between the reinforcement and the matrix, and this is an area where the spatial resolution of analytical TEM is required in order to characterise any interaction. The recent work on Ti6A14V/TiC and Ti24All INb/TiC composites has illustrated this very clearly. Even after heat treatments of 50h at 1100°C the TiC appears to be unaffected as assessed by both optical and scanning electron microscopy. Only when TEM is used is it possible to see that there has been any interaction.

Electron Microscopy of Metal-Matrix Composites

1970 ◽  
Vol 28 ◽  
pp. 404-405
Author(s):  
A. Lawley ◽  
M. R. Pinnel ◽  
A. Pattnaik
Keyword(s):  
Electron Microscopy ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Critical Evaluation ◽  
Elastic Behavior ◽  
Matrix Composites ◽  
Directionally Solidified ◽  
Fracture Characteristics ◽  
Broad Program

As part of a broad program on composite materials, the role of the interface on the micromechanics of deformation of metal-matrix composites is being studied. The approach is to correlate elastic behavior, micro and macroyielding, flow, and fracture behavior with associated structural detail (dislocation substructure, fracture characteristics) and stress-state. This provides an understanding of the mode of deformation from an atomistic viewpoint; a critical evaluation can then be made of existing models of composite behavior based on continuum mechanics. This paper covers the electron microscopy (transmission, fractography, scanning microscopy) of two distinct forms of composite material: conventional fiber-reinforced (aluminum-stainless steel) and directionally solidified eutectic alloys (aluminum-copper). In the former, the interface is in the form of a compound and/or solid solution whereas in directionally solidified alloys, the interface consists of a precise crystallographic boundary between the two constituents of the eutectic.

scholarly journals Predictive Computational Model for Damage Behavior of Metal-Matrix Composites Emphasizing the Effect of Particle Size and Volume Fraction

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2143
Author(s):  
Shaimaa I. Gad ◽  
Mohamed A. Attia ◽  
Mohamed A. Hassan ◽  
Ahmed G. El-Shafei
Keyword(s):  
Finite Element ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Volume Fraction ◽  
Particulate Composites ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Zone Method ◽  
Stress Strain ◽  
The Matrix

In this paper, an integrated numerical model is proposed to investigate the effects of particulate size and volume fraction on the deformation, damage, and failure behaviors of particulate-reinforced metal matrix composites (PRMMCs). In the framework of a random microstructure-based finite element modelling, the plastic deformation and ductile cracking of the matrix are, respectively, modelled using Johnson–Cook constitutive relation and Johnson–Cook ductile fracture model. The matrix-particle interface decohesion is simulated by employing the surface-based-cohesive zone method, while the particulate fracture is manipulated by the elastic–brittle cracking model, in which the damage evolution criterion depends on the fracture energy cracking criterion. A 2D nonlinear finite element model was developed using ABAQUS/Explicit commercial program for modelling and analyzing damage mechanisms of silicon carbide reinforced aluminum matrix composites. The predicted results have shown a good agreement with the experimental data in the forms of true stress–strain curves and failure shape. Unlike the existing models, the influence of the volume fraction and size of SiC particles on the deformation, damage mechanism, failure consequences, and stress–strain curve of A359/SiC particulate composites is investigated accounting for the different possible modes of failure simultaneously.

scholarly journals Interfacial Aspects of Metal Matrix Composites Prepared from Liquid Metals and Aqueous Solutions: A Review

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1400
Author(s):  
Peter Baumli
Keyword(s):  
Aqueous Solutions ◽  
Physical Properties ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Liquid Metals ◽  
Interfacial Phenomena ◽  
Matrix Composites ◽  
Good Adhesion ◽  
Mechanical And Physical Properties ◽  
The Matrix

The paper reviews the preparation of the different metallic nanocomposites. In the preparation of composites, especially in the case of nanocomposites, interfacial phenomena play an important role. This review summarizes the literature on various interfacial phenomena, such as wettability and reactivity in the case of casting techniques and colloidal behavior in the case of electrochemical and electroless methods. The main contribution of this work lies in the evaluation of collected interfacial phenomena and difficulties in the production of metal matrix composites, for both nano-sized and micro-sized reinforcements. This study can guide the composite maker in choosing the best criteria for producing metal matrix composites, which means a real interface with good adhesion between the matrix and the reinforcement. This criterion results in desirable mechanical and physical properties and homogenous dispersion of the reinforcement in the matrix.

Creep Deformation of Particle-Strengthened Metal-Matrix Composites

1989 ◽  
Vol 111 (1) ◽  
pp. 99-105 ◽  
Author(s):  
Z. G. Zhu ◽  
G. J. Weng
Keyword(s):  
Constitutive Equation ◽  
Metal Matrix Composites ◽  
Creep Strain ◽  
Creep Deformation ◽  
Creep Resistance ◽  
Metal Matrix ◽  
Order Approximation ◽  
Stress Redistribution ◽  
Matrix Composites ◽  
The Matrix

A multiaxial theory of creep deformation for particle-strengthened metal-matrix composites is derived. This derivation is based on the observation that there are two major sources of creep resistance in such a system. The first, or metallurgical effect, arises from the increased difficulty of dislocation motion in the presence of particles and is accounted for by a size- and concentration dependent constitutive equation for the matrix. The second, or mechanics effect, is due to the continuous transfer of stress from the ductile matrix to the hard particles and the corresponding stress redistribution is also incorporated in the derivation. Both power-law creep and exponential creep in the matrix, each involving the transient as well as the steady state, are considered. The constitutive equations thus derived can provide the development of creep strain of the composite under a combined stress. The multiaxial theory is also simplified to a uniaxial one, whose explicit stress-creep strain-time relations at a given concentration of particles are also given by a first- and second-order approximation. The uniaxial theory is used to predict the creep deformation of an oxide-strengthened cobalt, and the results are in reasonably good agreement with the experiment. Finally, it is demonstrated that a simple metallurgical approach without considering the stress redistribution between the two constituent phases, or a simple mechanics approach without using a modified constitutive equation for the metal matrix, may each underestimate the creep resistance of the composite, and, therefore, it is important that both factors be considered in the formulation of such a theory.

Transmission Electron Microscope Specimen Preparation of Metal Matrix Composites Using the Focused Ion Beam Miller

2000 ◽  
Vol 6 (5) ◽  
pp. 452-462 ◽  
Author(s):  
Julie M. Cairney ◽  
Robert D. Smith ◽  
Paul R. Munroe
Keyword(s):  
Electron Microscope ◽  
Metal Matrix Composites ◽  
Transmission Electron Microscope ◽  
Metal Matrix ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Matrix Composites ◽  
Transmission Electron ◽  
The Matrix ◽  
Ceramic Reinforcement

AbstractTransmission electron microscope samples of two types of metal matrix composites were prepared using both traditional thinning methods and the more novel focused ion beam miller. Electropolishing methods were able to produce, very rapidly, thin foils where the matrix was electron transparent, but the ceramic reinforcement particles remained unthinned. Thus, it was not possible in these foils to study either the matrix-reinforcement interface or the microstructure of the reinforcement particles themselves. In contrast, both phases in the composites prepared using the focused ion beam miller thinned uniformly. The interfaces in these materials were clearly visible and the ceramic reinforcement was electron transparent. However, microstructural artifacts associated with ion beam damage were also observed. The extent of these artifacts and methods of minimizing their effect were dependent on both the materials and the milling conditions used.

A study on kerf characteristics of hybrid aluminium 7075 metal matrix composites machined using abrasive water jet machining technology

2016 ◽  
Vol 232 (4) ◽  
pp. 690-704 ◽  
Author(s):  
KSK Sasikumar ◽  
KP Arulshri ◽  
K Ponappa ◽  
M Uthayakumar
Keyword(s):  
Electron Microscopy ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Traverse Speed ◽  
Water Jet ◽  
Matrix Composites ◽  
Abrasive Water Jet ◽  
Abrasive Water Jet Machining ◽  
Kerf Angle ◽  
Scanning Electron

Metal matrix composites are difficult to machine in traditional machining methods. Abrasive water jet machining is a state-of-the art technology which enables machining of practically all engineering materials. This article deals with the investigation on optimization of process parameters of abrasive water jet machining of hybrid aluminium 7075 metal matrix composites with 5%, 10% and 15% of TiC and B4C (equal amount of each) reinforcement. The kerf characteristics such as kerf top width, kerf angle and surface roughness were studied against the abrasive water jet machining process parameters, namely, water jet pressure, jet traverse speed and standoff distance. Contribution of these parameters on responses was determined by analysis of variance. Regression models were obtained for kerf characteristics. Contribution of traverse speed was found to be more than other parameters in affecting top kerf width. Water jet pressure influenced more in affecting kerf angle and surface finish. The microstructures of machined surfaces were also analysed by scanning electron microscopy. The scanning electron microscopy investigations exposed the plastic deformation cutting of hybrid 7075 aluminium metal matrix composite. X-ray diffraction analysis results proved the non-entrapment of abrasive particle on the machined surface.

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