Analysis of Coefficient of Thermal Expansion and Thermal Conductivity of Bi-Modal SiC/A356 Composites Fabricated via Powder Metallurgy Route

Author(s):  
Preetkanwal Singh Bains ◽  
H. S. Payal ◽  
Sarabjeet Singh Sidhu

The present study investigates the thermal conductivity and coefficient of thermal expansion of bimodal SiCp reinforced Aluminum matrix composites formed via powder metallurgy method. The after-effects of proportion of particulate reinforcement as size distribution and sintering parameters on the thermal properties have been explored. The Box-Behnken design for response surface methodology was adopted to recognize the significance of chosen variables on the thermal conductivity and coefficient of thermal expansion of the composite. It is witnessed that the thermal conductivity and coefficient of thermal expansion enhanced due to increase in fine SiC particulates volume fraction. It has been exhibited that the fine SiC particulates (37μm) doped Al-matrix occupied interstitial positions and developed continuous SiC-matrix network. SEMs were conducted to evaluate the microstructure architecture for MMCs.

1993 ◽  
Vol 323 ◽  
Author(s):  
Shy-Wen Lai ◽  
D. D. L. Chung

AbstractAluminum-matrix composites containing AIN or SiC particles were fabricated by vacuum infiltration of liquid aluminum into a porous particulate preform under an argon pressure of up to 41 MPa. Al/AIN was superior to Al/SiC in thermal conductivity. At 59 vol.% AIN, Al/AlN had a thermal conductivity of 157 W/m. °C and a thermal expansion coefficient of 9.8 × 10−-6°C−1 (35–100 °C). Al/AlN had similar tensile strength and higher ductility compared to Al/SiC of a similar reinforcement volume fraction at room temperature, but exhibited higher tensile strength and higher ductility at 300–400°C. The ductility of Al/AlN increased with increasing temperature from 22 to 400°C, while that of Al/SiC did not change with temperature. The superior high temperature resistance of Al/AlN is attributed to the lack of a reaction between Al and AIN, in contrast to the reaction between Al and SiC in AI/SiC.


2011 ◽  
Vol 320 ◽  
pp. 297-302
Author(s):  
Cheng Chen ◽  
Hua Shun Yu ◽  
Jing Jing Zhang ◽  
Wei Zhang ◽  
Shou Hui Wang

In this study, SiC particles reinforced aluminum matrix composite was successfully fabricated using powder metallurgy technique followed by hot extrusion. The phases were identified by XRD and the microstructures were observed by SEM. The results showed that only Al and SiC phases existed in the composite, SiC particulates were well distributed in the aluminum matrix and the interface between Al and SiC was clean and well combined. Meanwhile, thermal conductivity and coefficient of thermal expansion of the composite were investigated, the research showed that thermal conductivity decreased as SiCp content increased because of poor thermal conductivity of SiCp and increased crystal defects forming during the fabrication process. And the same to thermal conductivity, coefficient of thermal expansion of the composite decreased as SiCp content increased because SiCp can acted as obstacles to the motion of dislocations, which can hinder the hot movement of electronics.


Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4030 ◽  
Author(s):  
Amélie Veillère ◽  
Hiroki Kurita ◽  
Akira Kawasaki ◽  
Yongfeng Lu ◽  
Jean-Marc Heintz ◽  
...  

Aluminum matrix composites reinforced with carbon fibers or diamond particles have been fabricated by a powder metallurgy process and characterized for thermal management applications. Al/C composite is a nonreactive system (absence of chemical reaction between the metallic matrix and the ceramic reinforcement) due to the presence of an alumina layer on the surface of the aluminum powder particles. In order to achieve fully dense materials and to enhance the thermo-mechanical properties of the Al/C composite materials, a semi-liquid method has been carried out with the addition of a small amount of Al-Si alloys in the Al matrix. Thermal conductivity and coefficient of thermal expansion were enhanced as compared with Al/C composites without Al-Si alloys and the experimental values were close to the ones predicted by analytical models.


2021 ◽  
Vol 63 (4) ◽  
pp. 350-355
Author(s):  
Mehmet Ayvaz ◽  
Hakan Cetinel

Abstract To be able to successfully produce ceramic-reinforced aluminum matrix composites by using the powder metallurgy method, the wetting of ceramic reinforcements should be increased. In addition, the negative effects of the oxide layer of the aluminum matrix on sinterability should be minimized. In order to break the oxide layer, the deoxidation property of Mg can be used. Furthermore, by creating a liquid phase, both wettability and sinterability can be improved. In this study, the effects of Mg and Cu alloy elements and sintering phase on the wettability, sinterability, and mechanical properties of Al/B4C composites were investigated. For this purpose, various amounts (5, 10, 20, and 30 wt.-%) of B4C reinforced Al5Cu and Al5Mg matrix composites were produced by the powder metallurgy method. After pressing under 400 MPa pressure, composite samples were sintered for 4 hours. The sintering was carried out in two different groups as solid phase sintering at 560 °C and liquid phase sintering at 610 °C. Despite the deoxidation effect of Mg in Al5Mg matrix composites, higher mechanical properties were determined in Al5Cu composites which were sintered in liquid phase because wettability increased. The highest mechanical properties were obtained in the 20 wt.-% B4C reinforced Al5Cu sample sintered in liquid phase.


2018 ◽  
Vol 53 (11) ◽  
pp. 8180-8192 ◽  
Author(s):  
Nabil Chamroune ◽  
Diaa Mereib ◽  
Florence Delange ◽  
Nathalie Caillault ◽  
Yongfeng Lu ◽  
...  

2010 ◽  
Vol 152-153 ◽  
pp. 545-549
Author(s):  
Qing Ping Wang ◽  
Yu Cheng Wu ◽  
Fan Fei Min

Fly ash particles reinforced aluminum matrix composites were fabricated by powder metallurgy method. The influence of different fly ash content on hardness, the friction and wear behavior of the composites were investigated at a constant sliding velocity of 400r/min. The worn surfaces of composites were observed by scanning electron microscope, and worn mechanism of composites was discussed. The results showed that the hardness of composites increased first and then decreased with fly ash content increasing. Under the lower loads and at the lower fly ash content, the friction co-efficient is steadily lower than that of Al alloy matrix. The wear resistance of composites increased with the volume fraction of fly ash particles and the wear mechanism was characterized as abrasive wear and adhesive wear.On the other hand, the wear mechanisms in the composites have been transformed with increasing load and fly ash volume; it mainly was delamination wear and abrasive wear.


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