Simultaneous Effects of Carbon Nanotube Content and Diameter Size on Microstructure and Mechanical Properties of Double Pressed Double Sintered Al/Carbon Nanotube Nanocomposites (Mar, 10.1007/s11665-022-06798-1, 2022)

This work examined the effect of content (1–12wt.%) and diameter size (8, 20, and 40 nm) of carbon nanotubes (CNTs) on the microstructure and mechanical behavior of aluminum matrix nanocomposites. After mixing powders, using the ball milling technique, the nanocomposites were fabricated by Double-Pressing Double-Sintering (DPDS) process. Al/CNTs nanocomposites were characterized by Raman spectroscopy, x-ray diffraction, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The characterization of nanocomposites revealed that the CNTs content and diameter size had an important effect on the formation of Al/CNTs interface, clustering of CNTs, and mechanical properties. In addition, aluminum carbide (Al4C3) was observed in the interface of Al/CNTs. Under the same conditions, the tendency of CNTs with a diameter of 8 nm (the smallest diameter) was higher to form agglomerate and Al4C3 than other diameters of 20 and 40 nm. The maximum hardness value (94.8HV) and compressive strength (293 MPa) were obtained when CNTs diameter size was 40 nm in Al-8wt.% CNTs. The fracture surfaces indicated CNTs pull-out and bridging between the aluminum matrix. One of the significant achievements of this paper is the possibility of adding high amounts of CNTs in double-pressed double-sintered Al-based nanocomposites, which can improve the properties up to 8 wt.%. © 2022, ASM International.