Dispersion of multiwalled carbon nanotubes into a diglyme solution, electrodeposition of aluminum-based composite, and improvement of hardness

Composites of metals and carbon nanotubes (CNTs) are of interest due to their better mechanical properties compared to neat materials. Aluminum (Al) composites with multi-walled carbon nanotubes (MWCNTs) have been prepared by room-temperature electrodeposition in a relatively inexpensive and safe organic solvent, i.e. diglyme (G2). Successful dispersion of MWCNTs in an AICI(3)-G2 electrodeposition bath was achieved by surface modification i.e. acid treatment of MWCNTs, similar to the case of aqueous baths. Scanning electron microscopy images showed that MWCNTs filled and/or bridged the gap between Al particles, which can be attributed to the high Vickers hardness of 205 +/- 14 HV, exceeding 160 HV for Al-MWCNTs obtained by powder metallurgical methods. Additionally, while the Vickers hardness of electroplated Al-MWCNTs composites has been reported to be 75 HV, an almost three times harder material is reported in the present study. (C) 2019 Elsevier B.V. All rights reserved.