Evolution of Microstructure and Mechanical Properties of CNTs/Al-Mg Composites Prepared by Powder Metallurgy

Abstract

In this research, 1 wt% carbon nanotubes/aluminum 5 wt% Mg (CNTs/Al-Mg) composites were fabricated using powder metallurgy and hot pressing method. Dislocation density increases and dislocation cell structure is formed in Al-Mg particles for the repeared flattening, cold welding, fracturing and rewelding during ball milling. The horizontal stirring high-energy ball milling method can uniformly disperse 1 wt% CNTs in Al-Mg matrix powders, and can form an effective composite interface bonding. Some parts of the carbon nanotubes are twisted to form carbon nanoonions. After 90 min of ball milling, the tensile strength of the composite material obtained by hot pressing reached the maximum value, which was 244 MPa, which was increased by 31% compared with the composite materials none milled.