Effect of Milling Time on Microstructure and Properties of AA6061/MWCNTS Composite Powders / Wpływ Czasu Mielenia Na Strukturę I Własności Proszk Ów Kompozytowyc H AA6061/MWCNTS

Abstract

The main purpose of this work is to determine the effect of milling time on microstructure as well as technological properties of aluminium matrix nanocomposites reinforced with multi-walled carbon nanotubes (MWCNTs) using powder metallurgy techniques, including mechanical alloying. The main problem of the study is the agglomeration and uneven distribution of carbon nanotubes in the matrix material and interface reactivity also. In order to reach uniform dispersion of carbon nanotubes in aluminium alloy matrix, 5÷20 h of mechanical milling in the planetary mill was used. It was found that the mechanical milling process has a strong influence on the characteristics of powders, by changing the globular morphology of as-received powder during mechanical milling process to flattened one, due to particle plastic deformation followed by cold welding and fracturing of deformed and hardened enough particles, which allows to obtain equiaxial particles again. The obtained composites are characterised by the structure of evenly distributed, disperse reinforcing particles in fine grain matrix of AA6061, facilitate the obtainment of higher values of mechanical properties, compared to the initial alloy. On the basis of micro-hardness, analysis has found that a small addition of carbon nanotubes increases nanocomposite hardness.

Investigation of Mechanical and Tribological Properties of AA6061/MWCNT/B4C Hybrid Metal Matrix Composite

“…Powder metallurgy has used a range of aluminium powders and CNT volume fractions to significant effect. For pre-and post-HIP, the tribological, density, stiffness, and compressive strength performance of the aluminium matrix nanocomposite were studied [32][33][34].…”

Bulletin of the Polish Academy of Sciences: Technical Sciences

“…From previous literature, it is reported that the mechanical alloying process parameters could influence the mechanical properties of Al and its composites. Earlier researchers had experimented the effects of milling parameters on powders and suggested the most influencing factors are milling time, Ball To Powder Ratio (BTPR) and milling speed [8,9]. Fogagnolo et al [10] studied the effects of mechanical alloying process on microstructure and mechanical properties of the Al and its composites.…”

The Influence of the Temperature and Ageing Time on the NiCr23Co12Mo Alloy Microstructure

“…In the light of European legal requirements, domestic resources of brown and hard coal, depreciation of most of operating power units in Poland, as well as energy security, trends in research and development of energy aim to build a modern power units with ultra-cool supercritical parameters, e.g. a temperature of 650-740 °C and pressure 30-35 MPa [1][2][3][4][5][6].…”