Structure Analysis of the Modified Cast Metal Matrix Composites by Use of the Rve Theory

2013 ◽  
Vol 58 (2) ◽  
pp. 357-360 ◽  
Author(s):  
P. Kurtyka ◽  
N. Rylko
Keyword(s):  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Three Dimensional ◽  
Volume Element ◽  
Matrix Composites ◽  
Reinforced Composites ◽  
Initial State ◽  
Reinforcing Particles ◽  
Three Dimensional Models ◽  
Properties Of Composites

The paper presents applications of a new theory of the representative volume element (RVE) based on the Mityushev- Eisenstein-Rayleigh sums (M-sums) to describe particle-reinforced composites. This theory is applied to study F3K.10S metal matrix composites reinforced SiC particles. The most important M-sum e2 is calculated for the initial state as e2 = -0.00206281. This shows considerable heterogeneity of distribution of reinforcing particles and its anisotropic properties. Further, the results are compared with the results obtained by the FSP. It is established that the use of a single FSP process causes a significant change in the distribution of particles reinforcing phase when the value e2 becomes 3.19488. It follows from Mityushev’s theory that e2=π corresponds to isotropic distributions. The article confirms that the new RVE theory resolves the problem of the constructive pure geometrical description of the properties of composites. Further work requires the optimization and extension of the theory to three-dimensional models.

Characterization of Metal Matrix Composites by Synchrotron Refraction Computed Topography

2010 ◽  
Vol 638-642 ◽  
pp. 967-972
Author(s):  
Bernd R. Müller ◽  
Axel Lange ◽  
M. Harwardt ◽  
M.P. Hentschel
Keyword(s):  
Computed Tomography ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
High Performance ◽  
Three Dimensional ◽  
Matrix Composites ◽  
X Rays ◽  
X Ray ◽  
Surface And Interface ◽  
Federal Institute

X-ray computed tomography is an important tool for evaluating the three dimensional microstructure of modern materials non-destructively. To resolve material structures in the micrometre range and below high brilliance synchrotron radiation has to be taken. But materials of low absorption or mixed phases show a weak absorption contrast at there interfaces. A Contrast enhancement can be achieved by exploiting the refraction of X-rays at interfaces. This technique was developed and applied at the NDT department of the Federal Institute for Materials Research and Testing (BAM) during the last decade. It meets the actual demand for improved non-destructive characterisation of high performance composites, ceramics and other low density materials and components. The technique is based on Ultra Small Angle Scattering (USAXS) by micro structural elements causing phase related effects like refraction and total reflection at a few minutes of arc as the refractive index of X-rays is nearly unity. The extraordinary refraction contrast of inner surfaces is far beyond absorption effects and hence especially useful for materials of low absorption or mixed phases, showing similar X-ray absorption properties. Crack orientation and fibre-matrix debonding in plastics, polymers, ceramics and metal-matrix-composites after cyclic loading and hydro thermal aging can be visualized. By combining the refraction technique with the computed tomography technique the three dimensional imaging of the micro structure of the materials is obtained. In most cases the investigated inner surface and interface structures correlate to mechanical properties. Recent results with a sub-micrometer resolution will be presented.

Oxidation Behavior of BN/(Al-Mg) Metal Matrix Composites

2005 ◽  
Vol 475-479 ◽  
pp. 975-978
Author(s):  
W.S. Woo ◽  
Woo Gwang Jung ◽  
Dong Bok Lee
Keyword(s):  
Metal Matrix Composites ◽  
Oxidation Resistance ◽  
Metal Matrix ◽  
Oxidation Behavior ◽  
Oxidation Mechanism ◽  
Pressureless Infiltration ◽  
Matrix Composites ◽  
Preferential Oxidation ◽  
Reinforcing Particles ◽  
Infiltration Technique

Metal matrix composites (MMCs) that consisted of Al-Mg matrix reinforced with initially added BN particles were fabricated using the pressureless infiltration technique, and their oxidation behavior was investigated at 500 and 550oC in air. Initially added BN particles were partly consumed to make AlN, as another reinforcing particles. Another reaction product was MgAlB2 dispersoids. Despite of the presence of these reinforcing particles, the oxidation resistance was not good owing to the formation of MgO-rich scale due to the preferential oxidation of Mg in the MMCs. Detailed microstructures and oxidation mechanism of the prepared MMCs are proposed.

A Computational Approach for the Constitutive Modeling of Elastoplastic Behavior of Metal Matrix Composites

2016 ◽  
Vol 14 (05) ◽  
pp. 1750058 ◽  
Author(s):  
M. U. Siddiqui ◽  
Abul Fazal M. Arif
Keyword(s):  
Composite Materials ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Three Dimensional ◽  
Constitutive Models ◽  
Computational Approach ◽  
Matrix Composites ◽  
Elastoplastic Behavior ◽  
Alumina Composite

Computational homogenization provides an excellent tool for the design of composite materials. In the current work, a computational approach is presented that is capable of estimating the elastic and rate-independent plastic constitutive behavior of metal matrix composites using finite element models of representative volume elements (RVEs) of the composite material. For this purpose, methodologies for the generation of three-dimensional computational microstructures, size determination of RVEs and the homogenization techniques are presented. Validation of the approach is carried out using aluminum–alumina composite samples prepared using sintering technique. Using the homogenized material response, effective constitutive models of the composite materials have been determined.

The Minimum Representative Volume Element Size for Coefficient of Thermal Expansion of Particle Reinforced Metal Matrix Composites

2013 ◽  
Vol 773 ◽  
pp. 435-440
Author(s):  
X.X. Zhang ◽  
B.L. Xiao ◽  
Z.Y. Ma
Keyword(s):  
Thermal Expansion ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Coefficient Of Thermal Expansion ◽  
Three Dimensional ◽  
Analytical Models ◽  
Matrix Composites ◽  
Element Size ◽  
Representative Volume Element Size ◽  
Sharp Edges

A 3D realistic microstructure based computational homogenization model is proposed, in order to determine the temperature dependent effective coefficient of thermal expansion of particle reinforced metal matrix composites The model employed three-dimensional realistic microstructures with different domain sizes, where particles had random shape, sharp edges and were randomly distributed. The unit cell microstructure based model and classical analytical models were also presented for comparison. As an illustration of the model, a 17% vol. SiCpreinforced 2124Al composite was investigated. Its minimum RVE size is found to beδ= 15, whereδis called the size ratio and defined by the ratio between the side length of microstructure and the mean particle radius.

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