Effect of high ratio of reinforcement particle size to matrix powder size and volume fraction on microstructure, densification and tribological properties of SiC p reinforced metal matrix composites manufactured via hot pressing method

Author(s):  
Ege Anıl Diler ◽  
Amir Ghiami ◽  
Rasim Ipek
2021 ◽  
Author(s):  
Qian Zhang

An analytical model for predicitng the crack inititation life of low cycle fatique (LCF) of discontinuously reinforced metal matrix composites (DR-MMCs) has been proposed. The effects of the volume fraction Vf cyclic strain hardening exponent n' and cyclic strength coefficient K' on the LCF crack initiation life of DR-MMCs were analyzed. While both the lower level of the plastic strain amplitude and the lower Vf were found to increase the LCF crack initiation resistance, the effects of n' and K' were more complicated. By considering the enhanced dislocation density in the matrix and the load bearing effect of particles, a quantitative relationship between the LCF life of DR-MMCs and particle size was also derived. This model showed that a decreasing particle size results in a longer LCF life. The theoretical predictions based on the proposed models were found to be in good agreement with the experimental data reported in the literature.


2011 ◽  
Vol 194-196 ◽  
pp. 1437-1441 ◽  
Author(s):  
Chun Lin He ◽  
Jian Ming Wang ◽  
Qing Kui Cai

The texture development was investigated in the extruded Al and Al metal matrix composites (MMCs) reinforced with SiC particles of different sizes and volume fractions. During extrusion, both the unreinforced Al and the MMCs develop a strong fiber texture with two components: <111> and <100>. When SiC is introduced into aluminum, the main component of texture is not modified, but the intensity of the component evolves with the volume fraction and average size of SiC particles. For the MMCs reinforced with 3.5μm SiC particles, the texture intensity of the Al matrix tends to decrease as the SiC volume fraction increases, and it is lower than that in the unreinforced Al. However, for the MMCs reinforced with 25 nm and 150 nm SiC particles, the texture intensity of the Al matrix is higher than that in the unreinforced matrix, and it increases with increasing the SiC volume fraction. It is found that superfine particles may introduce some new component into the deformation texture, and the texture intensity increases as the SiC particle size decreases.


Author(s):  
M. N. A. Nasr ◽  
A. Ghandehariun ◽  
H. A. Kishawy

One of the main challenges encountered in modeling the behavior of metal matrix composites (MMCs) during machining is the availability of a suitable constitutive equation. Currently, the Johnson–Cook (J–C) constitutive equation is being used, even though it was developed for homogeneous materials. In such a case, an equivalent set of homogeneous parameters is used, which is only suitable for a particular combination of particle size and volume fraction. The current work presents a modified form of the J–C constitutive equation that suits MMCs, and explicitly accounts for the effects of particle size and volume fraction, as controlled parameters. Also, an energy-based force model is presented, which considers particle cracking and debonding based on the principles of fracture mechanics. In order to validate the new approach, cutting forces were predicted and compared to experimental results, where a good agreement was found. In addition, the predicted forces were compared to other analytical models available in the literature.


2001 ◽  
Vol 16 (6) ◽  
pp. 1614-1625 ◽  
Author(s):  
Cheryl Lau ◽  
Alexander Mukasyan ◽  
Aleksey Pelekh ◽  
Arvind Varma

Combustion synthesis (CS) of NiAl-based materials reinforced by TiB2 particles was investigated under both terrestrial and microgravity conditions. The synthesized metal matrix composites (MMC) are characterized by very fine (<1 μm) reinforced particulates, which have strong bonding along their entire surface with matrix (NiAl) and are distributed uniformly in it. It was found that microgravity leads to a decrease in the average TiB2 particle size, while higher volume fraction of NiAl component in the material leads to the formation of coarser reinforced particulates. The mechanism of structure formation of different MMCs during CS was identified by using the quenching technique. For example, it was shown that TiB2 grains appear due to crystallization from the complex (Ni–Al–Ti–B) liquid solution formed in the combustion front. An overall decrease of microstructural transformation rates was observed under microgravity.


2018 ◽  
Vol 25 (05) ◽  
pp. 1850109
Author(s):  
SARAVANAN MUTHUSAMY ◽  
GANESAN PANDI

Metal matrix composites are widely applied in the automotive and aircraft structural components. This work investigates the influence of mechanical and corrosion properties hybrid aluminium 2024 metal matrix composites having 5%, 10%, 15% and 20% of TiC and B4C (equal amount) reinforcement compositions. The increase in volume fraction of B4C and TiC particle in matrix alloy increases the hardness, yield strength, ultimate strength and decreases the ductility of the composite. SEM images show microstructure of the composites with particles having a different volume percentage of reinforcement. The uniform distribution of B4C and TiC particles is most predominant in composite fabrication and the reinforcement particle additions have proved improved corrosion resistance in AA2024–B4C–TiC MMCs.


2021 ◽  
Author(s):  
Qian Zhang

An analytical model for predicitng the crack inititation life of low cycle fatique (LCF) of discontinuously reinforced metal matrix composites (DR-MMCs) has been proposed. The effects of the volume fraction Vf cyclic strain hardening exponent n' and cyclic strength coefficient K' on the LCF crack initiation life of DR-MMCs were analyzed. While both the lower level of the plastic strain amplitude and the lower Vf were found to increase the LCF crack initiation resistance, the effects of n' and K' were more complicated. By considering the enhanced dislocation density in the matrix and the load bearing effect of particles, a quantitative relationship between the LCF life of DR-MMCs and particle size was also derived. This model showed that a decreasing particle size results in a longer LCF life. The theoretical predictions based on the proposed models were found to be in good agreement with the experimental data reported in the literature.


Author(s):  
Ritesh Raj ◽  
DG Thakur

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.


Sign in / Sign up

Export Citation Format

Share Document