The Influence of Interfacial and Structural Parameters on the Elastic Modulus of SiCp/6066Al Composites

2007 ◽  
Vol 546-549 ◽  
pp. 653-656
Author(s):  
Fu Sheng Pan ◽  
Wen Ming Wang ◽  
Yun Lu ◽  
Su Min Zeng
Keyword(s):  
Elastic Modulus ◽  
Volume Fraction ◽  
Poisson Ratio ◽  
Structural Parameters ◽  
The Matrix ◽  
Specific Elongation ◽  
Matrix Modulus ◽  
Particulate Volume Fraction ◽  
Optimal Approach ◽  
Particulate Volume

The effects of the interfacial parameters (interface/matrix modulus ratio, interface Poisson ratio and interface volume fraction) and the structural parameters (particulate volume fraction, particulate shape, arrangement pattern and dimensional variance mode) on the elastic modulus of SiCp/6066Al composites were calculated and analyzed. The results showed that component and interface performance significantly influenced the elastic modulus of the composite; but the particulate shape, arrangement pattern and dimensional variance mode were found to have little influence. This means that the effect of the above structural parameters can be negligible. The optimal approach to enhance the elastic modulus and specific elongation of a composite is to improve the interfacial bonding of the particulate. Optimal results are obtained when the interface modulus is 20% ~ 30% of the matrix modulus.

Microstructure and Mechanical Properties of In Situ TiB2/6061 Composites

2012 ◽  
Vol 535-537 ◽  
pp. 14-17
Author(s):  
Long Hua Zhong ◽  
Yu Tao Zhao ◽  
Song Li Zhang ◽  
Rong Wen
Keyword(s):  
Master Alloy ◽  
Volume Fraction ◽  
X Ray Diffraction ◽  
Melt Mixing ◽  
X Ray ◽  
Mixing Method ◽  
Particulate Volume Fraction ◽  
Ti Powder ◽  
Particulate Volume

In situ TiB2/6061 composites have been successfully synthesized through chemical reaction between 6061 master alloy, Al-3B master alloy and Ti powder. The composites fabricated by direct melt mixing method was investigated by Scanning Electron Microscope (SEM), Energy Dispersive x-ray Spectroscopy (EDS) and X-Ray Diffraction (XRD), The results shown the existence of TiB2particles. The size of most TiB2particles were just in micron level, and even reached to sub-micron level. The increase in microhardness and tensile strength for the as-prepared composites with 5% particulate volume fraction (PVF) are up to 26.8% and 51.2% respectively.

MEASUREMENT OF PARTICULATE VOLUME FRACTION IN A COFLOW DIFFUSION FLAME USING TRANSIENT THERMOCOUPLE TECHNIQUE

2004 ◽  
Vol 176 (5-6) ◽  
pp. 945-958 ◽  
Author(s):  
A. Rolando ◽  
A. D'Alessio ◽  
A. D'Anna ◽  
C. Allouis ◽  
F. Beretta ◽  
...  
Keyword(s):  
Diffusion Flame ◽  
Volume Fraction ◽  
Coflow Diffusion Flame ◽  
Particulate Volume Fraction ◽  
Particulate Volume

The modelling of the growth of soot particles during the pyrolysis and partial oxidation of aromatic hydrocarbons

1981 ◽  
Vol 377 (1769) ◽  
pp. 119-145 ◽  
Keyword(s):  
Condensed Phase ◽  
Volume Fraction ◽  
Growth Models ◽  
Scattered Light ◽  
Incident Shock ◽  
Optical Absorption Coefficient ◽  
Wide Range ◽  
Particulate Volume Fraction ◽  
Condensational Growth ◽  
Particulate Volume

Previous light-scattering studies on aerosols generated by hydrocarbon pyrolysis in incident shock flows have shown, given a constant particulate volume fraction, that the observed scattered-light intensities agree very closely with those predicted for the free-molecular coagulation of an aerosol having a self-preserving size distribution. One crucial obstacle to the extension of this simple model to include condensational growth has been the measurement of how the particulate volume fraction changes with time. For, not only does the condensed phase contain both soot (which absorbs infrared radiation) and molecular nuclear aromatic species (which do not), but this latter (black) material apparently condenses from the gaseous phase without change in optical absorption coefficient. The approach adopted here has therefore been to generate and test various growth models that span a wide range of assumptions about condensation and nucleation. Only two models, designated COAG and CONCO, can provide quantitative agreement between prediction and observation. Both models require that at any instant the infrared-transparent, light-absorbing polynuclear aromatic intermediates are either all in the gas phase or all in the condensed phase, the switch between the two states corresponding to an instantaneous, massive nucleation step. This interpretation is supported by the marked failure of all growth models based on different assumptions to match the observations. Extensions of the COAG and CONCO models to treat nucleation more realistically give essentially unchanged predictions over substantial domains of assumed initial values of particulate number density and volume fraction. This stability explains why the simple models can correctly describe the results obtained for many shocks spanning a range of temperature, hydrocarbon species and oxygen concentration, where substantial shock-to-shock variations in nucleation rates must exist. At critically low temperatures, with delayed and less rapid nucleation, the CONCO model and extensions thereof must be preferred to the COAG model because they give greater weight to condensational growth.

Identification of Structural Parameters of Metal Fibre Concrete Using Magnetic Approach

2013 ◽  
Vol 592-593 ◽  
pp. 157-160 ◽  
Author(s):  
Jiří Vala ◽  
Leonard Hobst
Keyword(s):  
Volume Fraction ◽  
Structural Parameters ◽  
Optimization Technique ◽  
Drying Shrinkage ◽  
Solid Material ◽  
Least Square ◽  
Material Structure ◽  
Destructive Testing ◽  
The Matrix ◽  
Homogenization Approach

Mechanical behaviour of concrete structures and their durability are conditioned by the reduction of cracking due to plastic and drying shrinkage and of permeability of concrete. This can be done using small metal particles, typically short steel fibres, randomly distributed in the concrete matrix. Since the technological requirements to the preparation and early-age treatment of such mixtures are rather demanding, some reliable a posteriori validation of expected solid material structure is needed. As alternatives to destructive testing, various low-invasive radiographic, electromagnetic, etc. approaches have been developed in the last decade. This paper demonstrates an original magnetic approach to the identification of volume fraction, macroscopic (in) homogeneity and orientation of particles in the matrix, using the Hall effect and the properties of solutions of the Laplace equation, as well as an advanced computational homogenization approach, coupled with the least-square based optimization technique.

The Strength of Fibres in All-Ceramic Composites

1986 ◽  
Vol 78 ◽  
Author(s):  
Kevin Kendall ◽  
N. Mcn. Alford ◽  
J. D. Birchall
Keyword(s):  
Elastic Modulus ◽  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Ceramic Composites ◽  
Fibre Volume ◽  
Matrix Cracking ◽  
Fibre Strength ◽  
All Ceramic ◽  
The Matrix ◽  
Fibre Matrix

ABSTRACTWhen considering the strength of a fibre reinforced ceramic composite, it is often assumed that the fibres retain their full strength of several GPa after cracking of the weaker matrix. The strength of the composite after matrix cracking is then calculated by the rule of mixtures as the product of fibre volume fraction and fibre strength. This paper demonstrates that such a calculation is not consistent with the principles of fracture mechanics for an isolated fibre embedded in an elastic matrix of the same elastic modulus, because the strength of the fibre is much reduced by the stress concentration arising from the matrix crack. Experimental measurements of the strength of a glass fibre embedded in a brittle matrix support the theory. The case of a fibre in a matrix of different elastic modulus is also considered, together with the proDlem of cracking along the fibre-matrix interface.

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