Characterization of Indentation-Induced “Particle Crowding” in Metal Matrix Composites

Materials ◽  
2004 ◽  
Author(s):  
R. Pereyra ◽  
Y.-L. Shen

A direct experimental characterization of reinforcement configuration in an indentation-deformed metal matrix composite is undertaken. The primary objective is to quantify the possible local increase in particle concentration, which has been proposed to cause inconsistency in the indentation hardness and the overall composite strength. Quantitative metallography on the post-indented material is carried out to measure the particle volume fraction. Multiple cross sections of an indentation are investigated with statistically significant results obtained. A distinct increase in particle concentration induced by the indentation is found. The spatial distribution of particle concentration is also examined in detail. The residual compressive stress field remained in the material upon unloading, as illustrated by the finite element analysis, is shown to be in qualitative agreement with the measurement.

2007 ◽  
Vol 353-358 ◽  
pp. 1263-1266
Author(s):  
Yi Wu Yan ◽  
Lin Geng ◽  
Ai Bin Li ◽  
Guo Hua Fan

By incorporating the Taylor-based nonlocal theory of plasticity, the finite element method (FEM) is applied to investigate the effect of particle size on the deformation behavior of the metal matrix composites. In the simulation, the two-dimensional plane strain and random distribution multi-particles model are used. It is shown that, at a fixed particle volume fraction, there is a close relationship between the particle size and the deformation behavior of the composites. The yield strength and plastic work hardening rate of the composites increase with decreasing particle size. The predicted stress-strain behaviors of the composites are qualitative agreement with the experimental results.


2018 ◽  
Vol 5 (8) ◽  
pp. 16800-16806 ◽  
Author(s):  
Y.J. Nithiya Sandhiya ◽  
M.M. Thamizharasan ◽  
B.V. Ajay Subramanyam ◽  
K.S. Vijay Sekar ◽  
S. Suresh Kumar

2019 ◽  
Vol 962 ◽  
pp. 210-217
Author(s):  
Yong Ming Guo ◽  
Nozomi Fukae

It is well known that the properties of materials are a function of their microstructural parameters. The FEM is a good selection for studies of three-dimensional microstructure-property relationships. In this research, the elastic-plastic micromechanical response of the particle volume fraction of two-phase materials have been calculated using a commercial software package of the FEM, some new knowledges on the microstructure-property relationships have obtained.


2021 ◽  
Vol 8 ◽  
Author(s):  
Jing Zhang ◽  
Jingyu Zhang ◽  
Haoyu Wang ◽  
Hongyang Wei ◽  
Changbing Tang ◽  
...  

A multi-scale finite element method is developed to simulate the irradiation process and postirradiation uniaxial tensile tests for metal-matrix composite fuels with representative volume elements (RVEs). The simulations of irradiation process are implemented under a wide range of burnup levels, with the irradiation effects on the mechanical constitutive relations of fuel particles and matrix taken into account comprehensively. The simulation results for the macroscopic postirradiation true stress/strain curves are obtained, excluding the irradiation-induced macroscopic deformations. The effects of particle fission density, temperature, and initial particle volume fraction are investigated and analyzed. The research results indicate that 1) a quasi-elastic stage appears during the postirradiation tension, which is mainly induced by the creation of high residual compressive stresses in the particles and matrix after irradiation; 2) with the increase of effective strains, new plastic deformations increase in the particles and matrix to result in the macroscale plastic stage; 3) the macroscale irradiation softening and hardening phenomena appear, which mainly stem from the weakened deformation resistance by the irradiation-induced plastic deformations in the matrix, the enlarged particle volume fraction after irradiation, and the irradiation hardening effects of metal matrix.


2019 ◽  
Vol 19 (07) ◽  
pp. 1950078
Author(s):  
Recep Ekici ◽  
Vahdet Mesut Abaci ◽  
J. N. Reddy

In this study, the effects of micro-structural parameters such as particle volume fraction, size and random distribution of Al 6061/SiC particulate metal-matrix composite (MMC) beams on free vibration response and the active vibration control are investigated. For this purpose, numerical particle-reinforced MMC (PRMMC) beam specimens were modeled with 3D finite elements, and the cubic-shaped reinforcing SiC particles were randomly distributed in Al 6061 metal matrix similar to an actual micro-structure. The particle size and especially volume fraction play an important role on the natural frequencies of the smart PRMMCs although they have no effect on the mode shapes. The random particle distribution has minor effect on the natural frequencies of the smart PRMMCs. With the increase of the feedback control gain, both the vibration amplitude and the suppression time are reduced reasonably. Increasing the particle volume fraction induces an important reduction in the damping time and the vibration amplitude for both the controlled and uncontrolled damped vibrations. Finally, increasing the particle size decreases the vibration suppression capacity and increases the vibration amplitude and time slightly. Random particle distribution had no obvious effect on the uncontrolled and controlled vibrations.


Author(s):  
Christopher O. Huber ◽  
Sascha Kremmer ◽  
Heinz E. Pettermann

Computational predictions on the tribological behavior of metal matrix composites (MMCs) are carried out. The influence of particle volume fraction and clustering of particles is investigated at different length scales. Finite Element simulations are performed on unit cells utilizing approaches from the field of ‘continuum mechanics of materials’. Models are based on the work of Segurado et al. [1], who used homogeneous, randomly distributed inclusions in a matrix phase with 30% particle volume fraction. In addition, the present work introduces modified unit cells with 10% volume fraction, with both homogeneous random and clustered distribution (Fig. 1). These modifications are derived from the original cell by either randomly removing inclusions in the first case, or from a predefined area in the second case.


Author(s):  
Y. J. Kim ◽  
S. M. Han ◽  
N. S. Woo

In directional drilling, it is difficult to adjust and control the cuttings, so it is very important to evaluate the flow characteristics of a drilling flow field. In this study, solid-liquid two-phase flow experiments have been carried out in non-Newtonian fluids for hole inclinations from vertical to 75 degrees, flow velocities from 0.33 m/s to 0.66 m/s, particle concentration from 4 to 16 %, and pipe rotations from 0 to 400 rpm. Pressure drop within the test section, and particle volume fraction are measured for the above test conditions. These quantities were influenced by particle concentration within the flow, pipe rotation, flow volume, and inclination of the annulus. Moreover, empirical correlations were developed for estimating friction coefficient and particle volume fraction inside annulus. The new correlations generated in this study are believed to be very practical and handy when they are used in the field. Therefore, this study can provide meaningful data for directional drillings.


Coatings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 64
Author(s):  
Qinxue Pan ◽  
Shuangyang Li ◽  
Yang Liu ◽  
Xiaoyu Xu ◽  
Meile Chang ◽  
...  

This study establishes a model for polymer-bonded explosives (PBX) using Digimat-FE. The model identifies the relationship between the material’s effective elastic modulus and the explosive particle volume fraction, shape and gradation, and porosity, as well as other factors. Further, finite element analysis of the stress distribution of the PBX composite material is performed, and the mathematical models between the ultrasonic attenuation coefficient, particle volume fraction, and ultrasonic frequency are established. Finally, an efficient ultrasonic nondestructive testing system is designed to determine the stress distribution and fine crack groups in the material. Experimental results indicate that the relative error of stress detection is within 15%, which meets the requirements of engineering applications.


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