Effect of reinforcement-particle-orientation anisotropy on the tensile and fatigue behavior of metal-matrix composites

Several deposition methods have been proposed for pre-deposition of reinforcement particle for preparation of surface metal matrix composite by Friction Stir Process. The method, which will effectively and homogeneously spread the reinforcement within processed zone, will be considered as best possible method.Homogeneous volumetric metal matrix composites can be fabricated by conventional casting and modified stir casting methods. Friction stir process (FSP) can be used as one of the best technique to fabricate surface modified metal matrix composites. In this research article, silicon carbide and graphite powder are used as reinforced materials and AA6061 is used as parent metal matrix material. FSP which is a versatile surface composite preparation technique is applied for fabrication of surface composite. Herein, single channel, multi-channel and perforated holes methods have been utilized for reinforcement deposition. As per the results, perforated blind holes method is reported as best method of pre deposition of powders. Finally, array of holes for pre-deposition of reinforcement powder improves approx 25% in ultimate tensile strength , 40% in micro-hardness and appreciable grain refinement are observed in metal matrix composite processed by FSP as compared to as received alloy.

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A New Model for Predicting Low Cycle Fatigue Behavior of Discontinuously Reinforced Metal Matrix Composites

10.32920/ryerson.14648949 ◽

2021 ◽

Author(s):

Qian Zhang

Keyword(s):

Particle Size ◽

Crack Initiation ◽

Metal Matrix Composites ◽

Metal Matrix ◽

Volume Fraction ◽

Low Cycle Fatigue ◽

Fatigue Behavior ◽

Plastic Strain Amplitude ◽

Strain Hardening Exponent ◽

Matrix Composites

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.

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Evaluation of Fatigue Behavior of Silicon Carbide Particles Reinforced with Magnesium Alloy Metal Matrix Composites

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.830.113 ◽

2020 ◽

Vol 830 ◽

pp. 113-118

Author(s):

Song Jeng Huang ◽

Murugan Subramani ◽

Addisu Ali ◽

Dawit Alemayehu ◽

Jong Ning Aoh ◽

...

Keyword(s):

Silicon Carbide ◽

Magnesium Alloy ◽

Metal Matrix Composites ◽

Metal Matrix ◽

Low Cycle Fatigue ◽

Fatigue Behavior ◽

Ambient Atmosphere ◽

Matrix Composites ◽

Silicon Carbide Particles ◽

Carbide Particles

To evaluate the fatigue behaviors of AZ61 magnesium alloy with different weight percentages (0, 1 and 2) of silicon carbide particles (SiCp) were fabricated through gravity casting method. In addition, stress-controlled low-cycle fatigue test of SiCp reinforced magnesium alloys AZ61 were performed in ambient atmosphere at room temperature using ASTM 606 standard specimens. Fatigue measurement results proved, that the fatigue life of SiCp reinforced metal matrix composites (MMCs) decreased with increasing SiCp content. However, the results of the cyclic ductility decreased owing to the presence of significant amount of SiCp, which induces the brittleness of fatigue properties. This is probably occurring because of increasing the SiCp content in the matrix causes highly localized plastic strain. In addition, a high concentration of stress results around the reinforcements particles regions initiate the crack leading to rapid failure of MMCs. Therefore, the SiCp did not act as a stress reliever and it behaves in a brittle manner for the crack propagation through the particles.

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