Transit Simulation Analysis for the Pressure Infiltration of Aluminum Melts Into Metal Matrix Composites

Author(s):  
J. Xie ◽  
R. S. Amano ◽  
P. M. Mohan Das ◽  
P. K. Rohatgi

Metal matrix composites (MMCs) possess superior modulus and strength due to the presence of the reinforce phase in the matrix metal in the form of short or long fibers and particles. Pressure infiltration can produce metal matrix composites containing much high volume fractions of reinforcement in the matrix. This process was recognized as one of the competitive routes to produce near-net shape MMC structures and has achieved successful commercial applications. A transit numerical simulation study is presented for tracking interfaces of two phases for the analysis of pressure infiltrating high-conductivity reinforcement carbon fibers by a molten metal under high-applied pressure conditions. The interface tracking method uses piecewise linear (PLIC) volume-of-fluid (VOF) methods with two-dimensional mesh. The method is coupled with the continuum surface force (CSF) algorithm for surface force modeling, a multi-grid solver support the resolution of large density ratio between the fluid and air. A fine scale infiltration filling flow phenomena between the fibers was solved so that the process parameters can be optimized to cast fibrous MMC engineering structures with fine and pore-free microstructure as well as satisfaction mechanical properties.

2012 ◽  
Vol 326-328 ◽  
pp. 471-476
Author(s):  
Katarzyna Gawdzińska ◽  
Dorota Nagolska ◽  
Janusz Grabian

Metal-matrix composites for many years have been widely used as engineering material all over the world, also in Poland. It is due to good construction properties, small specific gravity, ease of product formation, also large size items, diversity of manufacturing methods, and great possibilities of changing their properties depending on the output products used [. The authors of this study deal with metal-matrix composites made by casting. One of the methods they use in their research includes the saturation of the reinforcement structure (short disordered fibres pressed like felt, forming a profile, called preform) with metal liquid matrix under pressure. Phenomena occurring in the production of a composite material are similar to those taking place during making casts from traditional materials (cast steel, cast iron, non-ferrous metal alloys). This article is an overview of a problem encountered while detecting and describing defects of metal-matrix composite materials produced by saturation. It focuses on phenomena that take place during casting solidificationespecially the influence of the matrix (with different temperatures of liquid metal) on the reinforcement during its saturation and crystallisation of silicon plates on it.


2014 ◽  
Vol 592-594 ◽  
pp. 349-353 ◽  
Author(s):  
V. Ramakoteswara Rao ◽  
N. Ramanaiah ◽  
M.M.M. Sarcar

Aluminium alloy (AA7075) is largely used in various fields of transport applications, including marine, automotive and aviation and aerospace due to their high strength-to-density ratio. The present work deals with the influence of TiC on the mechanical behavior of AA 7075 composites. TiC is particularly attractive as it offers high hardness and elastic modulus, low density, good wettability yet low chemical reactivity with aluminium melts. The aluminium metal matrix composites (AMMCs) are produced as AA 7075 matrix metal and TiC particulates of an average size of 2µm as reinforced particles through stir casting, Magnesium added to the melt to overcome the wetting problem between TiC and liquid AA7075 metal. AMMCs are produced in different %weight of TiC ranging between 2 to 10%.These composites are characterized with optical, SEM and EDS analysis in as-cast condition and T6condition and hardness are predicted using macro vickers hardness tester. The test results showed increasing hardness of composites compared with matrix (AA7075) because of the presence of the increased reinforced material (TiC)


Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2143
Author(s):  
Shaimaa I. Gad ◽  
Mohamed A. Attia ◽  
Mohamed A. Hassan ◽  
Ahmed G. El-Shafei

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.


Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1400
Author(s):  
Peter Baumli

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.


Author(s):  
R. S. Amano ◽  
J. Xie ◽  
E. K. Lee ◽  
P. K. Rohatgi

A new experimental configuration for the casting of metal matrix composites (MMCs) using Al-4.5 wt pct Cu have been used to obtain finer microstructures around the fiber reinforcement. The new configuration allows the fibers to be extended out the mold and cooled by a heat sink. By doing so, the solidification can be made more rapid, and more primary alpha-aluminum phase can be formed on the surface of the fibers. It is believed that this can lead to improvement in the properties of the composite. CFD simulation of the solidification of Al-4.5 wt pct Cu in the casting process has been carried out by using commercial CFD code. Parametric studies on the effects of different processing parameters on solidification time have been simulated using the CFD code. These parameters include, but are not limited to, the pouring temperature of the liquid melt, sink temperature, fiber length extended out of the mold, the mold initial temperature, fiber conductivity, applied pressure, and fiber bundle diameter. Selected simulation results are compared with the available experimental data obtained from the UWM Center for Composites.


1989 ◽  
Vol 111 (1) ◽  
pp. 99-105 ◽  
Author(s):  
Z. G. Zhu ◽  
G. J. Weng

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.


2000 ◽  
Vol 6 (5) ◽  
pp. 452-462 ◽  
Author(s):  
Julie M. Cairney ◽  
Robert D. Smith ◽  
Paul R. Munroe

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.


2017 ◽  
Vol 08 (03n04) ◽  
pp. 1740004 ◽  
Author(s):  
G. R. Fernandes ◽  
A. S. Furtado ◽  
J. J. C. Pituba ◽  
E. A. De Souza Neto

Multiscale analyses considering the stretching problem in plates composed of metal matrix composites (MMC) have been performed using a coupled BEM/FEM model, where the boundary element method (BEM) and the finite element method (FEM) models, respectively, the macrocontinuum and the material microstructure, denoted as representative volume element (RVE). The RVE matrix zone behavior is governed by the von Mises elasto-plastic model while elastic inclusions have been incorporated to the matrix to improve the material mechanical properties. To simulate the microcracks evolution at the interface zone surrounding the inclusions, a modified cohesive fracture model has been adopted, where the interface zone is modeled by means of cohesive contact finite elements to capture the effects of phase debonding. Thus, this paper investigates how this phase debonding affects the microstructure mechanical behavior and consequently affects the macrostructure response in a multiscale analysis. For that, initially, only RVEs subjected to a generic strain are analyzed. Then, multiscale analyses of plates have been performed being each macro point represented by a RVE where the macro-strain must be imposed to solve its equilibrium problem and obtain the macroscopic constitutive response given by the homogenized values of stress and constitutive tensor fields over the RVE.


2012 ◽  
Vol 710 ◽  
pp. 365-370 ◽  
Author(s):  
Sujayakumar Prasanth ◽  
Kumaraswamy Kaliamma Ajith Kumar ◽  
Thazhavilai Ponnu Deva Rajan ◽  
Uma Thanu Subramonia Pillai ◽  
Bellambettu Chandrasekhara Pai

Magnesium metal matrix composites (MMCs) have been receiving attention in recent years as an attractive choice for aerospace and automotive applications because of their low density and superior specific properties. Using stir casting process, AZ91 magnesium alloy metal matrix composites have been produced with different weight percentages (5, 10, 15, 20 and 25) of silicon carbide particles (SiCp) addition. Microstructural characterization reveals uniform distribution of SiC particles with good interfacial bonding between the matrix and reinforcement. Electrical conductivity and Co-efficient of Thermal Expansion (CTE) measurements carried out on these composites have yielded better properties. Improved mechanical properties such as hardness, ultimate tensile strength, and compressive strength are obtained. The microfracture mechanisms involved during tensile fracture is analyzed and correlated with the properties obtained.


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