Fabrication of Al۷۰۷۵-MWCNT Composite Powder by Recycling Aluminum Alloy Chips Via High Energy Milling and Alloying

In this study, aluminum chips were milled in a planetary ball mill at different times and ball-to-powder weight ratios (BPRs). The resulting optimum powder was reinforced with ۱ wt% and ۲ wt% of multi-walled carbon nanotubes (MWCNTs). The effects of alloying time, BPR, and MWCNTs percentage on the morphology, distribution, and composition of the Al۷۰۷۵-MWCNT powder were investigated. The results showed that smaller particles with a limited size distribution can be obtainable by increasing BPR and decreasing mechanical milling time. A uniform dispersion of reinforcement (۲ wt%) was achieved at lower alloying times (۱۵ and ۳۰ min) and a higher BPR (۲۰:۱). Using XRD analysis, it was revealed that the carbon peaks are more clearly in ۲%-MWCNT powders than ۱%-MWCNT ones. The addition of MWCNTs led to reducing the particle size; this is confirmed by the data obtained from the XRD patterns and their analysis with the Williamson-Hall model. Machining chips were converted into composite powder by cost-effective mechanical milling and alloying method with a uniform distribution of MWCNTs, which is unique.

Keywords:

Metal matrix composite , Mechanical milling and alloying , Al۷۰۷۵-MWCNT composite , particle size , Particle distribution