Synthesis and Characterization of Aluminum-Carbon Nanotube Composite by Cryogenic Milling.

摘要

Cryogenic milling was studied for the ex situ strengthening of aluminum (Al) with carbon nanotubes (CNT). Characterization of mechanically alloyed Al-CNT powders was conducted in preparation for bulk powder processing to be used in cold spray. Al-CNT metal matrix composite powders with 5 wt.% and 10 wt.% CNT were synthesized by cryogenic milling of the blended component powders. Stearic acid was used as a process control agent to minimize agglomeration of the powders upon milling. CNT reinforcement of the Al powder was successfully obtained while maintain CNT structure after milling the powders for periods ranging between six and 90 minutes using a SPEX 6870 Freezer/Mill. Composition and properties of the Al-CNT composite was studied using X-ray diffraction, optical microscopy, nanoindentation, scanning electron microscopy (SEM), Raman spectroscopy, and laser diffraction particle size analysis.