Investigation of Thermal Expansion and Physical Properties of Carbon Nanotube Reinforced Nanocrystalline Aluminum Nanocomposite

2016 ◽  
Vol 71 (2) ◽  
pp. 165-174
Author(s):  
Manjula Sharma ◽  
Vimal Sharma

AbstractCarbon nanotube (CNT) reinforced nanocrystalline aluminum matrix composites are fabricated by a simple and effective physical mixing method with sonication. In this study, the microstructural characterisations and property evaluations of the nanocomposites were performed. The structural characterisations revealed that CNTs were dispersed, embedded, and anchored within the metal matrix. A strong interfacial adhesion appeared between CNTs and nanocrystalline aluminum as a result of the fabrication process. Raman and Fourier transform infrared spectroscopic studies also confirmed the surface adherence of CNTs with nanocrystalline aluminum matrix during the fabrication process. Thermal expansion behaviour of CNT-reinforced aluminum matrix composites was investigated up to 240°C using a dilatometer. The coefficient of thermal expansion of the nanocomposites decreased continuously with the increasing content of CNTs. The maximum reduction of 82% was found for 4 wt% CNTs in the nanocomposite. The coefficient of thermal expansion variation with CNTs was also compared with the predictions from the thermoelastic models. The expansion behaviour of the nanocomposites was correlated to the microstructure, internal stresses, and phase segregations. The electrical and thermal conductivity was also studied and was observed to decrease for all reinforced CNT weight fractions.

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.


2018 ◽  
Vol 7 (2.4) ◽  
pp. 117 ◽  
Author(s):  
Pranav Dev Srivyas ◽  
M S. Charoo

This review aims to explore the fundamental mechanical and tribological behavior Aluminum matrix composites (AMCs) reinforced with different reinforcements. Aluminum matrix composites are considered to be the new emerging class of materials which are having the tailored properties for specific applications. AMCs are the advanced engineering materials having superior properties as comparison to other conventional aluminum alloys. AMCs exhibits attractive properties such as high hardness, better yield strength, strength to weight ratio, high thermal conductivity, low coefficient of thermal expansion, superior wear and corrosion resistance. In recent times, because of these properties they have repealed keen interest for various potential applications in aerospace, automotive and various other structural applications.. Extensive research and development has been made in the Al-based MMCs with every possible alloy and different reinforcements so as to get the material of desired properties. By suitable use of different reinforcements in the Al metal matrix a wide range of properties combination can be obtained. The fundamental mechanical and tribological behavior of different reinforcements under dry and wet lubricated sliding conditions is recently being studied. It is reported that various reinforcement were successfully employed to decrease friction and wear in various applications. A comprehensive review is provided with the aim to analyze such properties of different reinforcements. 


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.


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.


Sign in / Sign up

Export Citation Format

Share Document