scholarly journals Onset of Adiabatic Shear Instability in Strain Gradient Dependent Metal Matrix Composites

2002 ◽  
Vol 3 (3-4) ◽  
Author(s):  
L. Η. Dai ◽  
L. F. Liu ◽  
Y. L. Bai
Keyword(s):  
Metal Matrix Composites ◽  
Strain Gradient ◽  
Metal Matrix ◽  
Adiabatic Shear ◽  
Shear Instability ◽  
Matrix Composites ◽  
Adiabatic Shear Instability

Effect of particle size and volume fraction on the strengthening mechanisms of boron carbide reinforced aluminum metal matrix composites

2018 ◽  
Vol 233 (4) ◽  
pp. 1345-1356 ◽  
Author(s):  
Ritesh Raj ◽  
DG Thakur
Keyword(s):  
Particle Size ◽  
Yield Strength ◽  
Metal Matrix Composites ◽  
Strain Gradient ◽  
Metal Matrix ◽  
Volume Fraction ◽  
Optical Microscope ◽  
Analytical Models ◽  
Matrix Composites ◽  
Strengthening Mechanisms

In the present work, 6061 Al–B4C metal matrix composites with different volume fractions (5, 10, 15 and 20 vol.%) have been fabricated by a low cost modified stir casting technique. The effect of varying particulate content on the microstructure of Al–B4C composites has been qualitatively characterized using a scanning electron microscope and an optical microscope. Tensile tests were performed to study the influence of varying reinforcement content on the strengthening behavior of fabricated composites. The composite’s yield strength increases significantly as the B4C content was increased from 0 to 20 vol.%. The enhancement in strength was elucidated on the basis of strengthening mechanisms characterized by load transfer, thermal dislocation, grain size, and strain gradient strengthening. The strengthening mechanisms were quantitatively analyzed and evaluated as a function of particle size and volume fraction. A critical particle size was found to be about 45 µm, below which the strengthening contributions from different mechanism increases remarkably. At a higher volume fraction of B4C, the effect of thermal dislocation strengthening becomes more dominant as compared to other mechanisms. Furthermore, the analytical models proposed by Ramakrishnan and Chen for predicting the yield strength of particulate reinforced metal matrix composites have been extended to take into account the contribution of strain gradient effect in the strengthening mechanism of composites.

scholarly journals Interface Cracking and Particulate Size Effect in Particle-Reinforced Metal-Matrix Composites

2008 ◽  
Vol 33-37 ◽  
pp. 591-596 ◽  
Author(s):  
Yue Guang Wei ◽  
Tie Ping Li ◽  
Hai Ou Xie
Keyword(s):  
Metal Matrix Composites ◽  
Strain Gradient ◽  
Metal Matrix ◽  
Ceramic Particle ◽  
Strain Gradient Plasticity ◽  
Experimental Result ◽  
Matrix Composites ◽  
Gradient Plasticity ◽  
Particulate Size ◽  
Interface Cracking

The mechanical behaviors of the ceramic particle-reinforced metal matrix composites are modeled based on the conventional theory of mechanism-based strain gradient plasticity presented by Huang et al. Two cases of interface features with and without the effects of interface cracking will be analyzed, respectively. Through comparing the result based on the interface cracking model with experimental result, the effectiveness of the present model can be evaluated. Simultaneously, the length parameters included in the strain gradient plasticity theory can be obtained.

Effect of Strain Gradients and Heterogeneity on Flow Strength of Particle Reinforced Metal-Matrix Composites

2002 ◽  
Vol 124 (2) ◽  
pp. 167-173 ◽  
Author(s):  
D-M. Duan ◽  
N. Q. Wu ◽  
M. Zhao ◽  
W. S. Slaughter ◽  
Scott X. Mao
Keyword(s):  
Particle Size ◽  
Metal Matrix Composites ◽  
Strain Gradient ◽  
Metal Matrix ◽  
Volume Fraction ◽  
Cell Model ◽  
Particle Volume Fraction ◽  
Matrix Composites ◽  
Particle Volume ◽  
Flow Strength

This paper deals with an analysis of the size effect on the flow strength of metal-matrix composites due to the presence of geometrically necessary dislocations. The work is based upon a cell model of uniaxial deformation. The deformation field is analyzed based on a requirement of the deformation compatibility along the interface between the particle and the matrix, which in turn is completed through introducing an array of geometrically necessary dislocations. The results of modelling show that the overall stress-strain relationship is dependent not only on the particle volume fraction but also on the particle size. It has been found that the material length scale in the strain gradient plasticity is dependent on the particle volume fraction, or in other words, on the relative ratio of the particle spacing to the particle size. The strain gradient is, besides the macro-strain and the particle volume fraction, inversely proportional to the particle size.

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