Carbon Nanotubes Reinforced Aluminum Matrix Composites

In the field of metal matrix composites, aluminum-based composites is an important area due to their low density, higher strength, anticorrosion and good workability, can be widely used in our daily life. Carbon nanotubes (CNTs) have emerged as materials with outstanding properties, such as low density, high specific strength, high specific modulus and so on, which makes them ideal reinforcements in composites. Carbon nanotubes reinforced aluminum matrix composites have a very good and attentive application perspective, the CNT-A1 composites fabricated have very excellent properties that does not exist in the single component. The CNT-Al composites can have numerous attractive applications in the aerospace, automotive, electronics industries and so on.However, only limited works are available on the fabrication of CNT-A1 composites by High-Energy Ball Milling, especially on the study of every parts of ball-milling, most of the efforts on CNT-Al composites have been concentrated on describing the properties of the product.There are two problems that need to be solved to fabricate CNT-A1 composites, one difficulty is make CNT uniformly dispersed in the matrix, the other is wetting between CNT and Al, this will improve bonding between CNT and Al.In this paper, carbon nanotubes reinforced aluminum matrix composites were fabricated by High-Energy Ball Milling, this paper firstly hade a study on the evolvement of particle size, particle size distributions of mixture powders, the evolvement of CNT's micrographs and the distribution of CNT in aluminum matrix at the process of ball milling, the effect of cold-pressing, vacuum sintering on the density, hardness and tensile strength were also studied. The microstructure of CNT was investigated by Raman, SEM and TEM, the component of composites were investigated by XRD, analyzed the methods to reinforce the interface bonding. The results showed that High-Energy Ball Milling here used successfully obtain CNT-A1 composited, not only can be seen better dispersion of the nanotubes in the aluminum matrix, also reinforced the interface bonding, the rotary speed, milling time and ball to powder weight ration hade an important influence on the distribution and structure of carbon nanotubes, the amount of CNT have double function on the properties, the properties of composites could be strengthen significantly when the amount of CNT was lower, but the properties would be decreased when the amount of CNT were higher, this would be attributed to the presence of CNT clusters in the composites, in the end, the mechanism of strengthening of CNT-Al composites were analyzed.