Energy-based ball milling process design and dispersion behavior of high content CNTs/Cu composites

The uniform dispersion of high content CNTs in metal matrix composites is a key problem restricting the preparation of materials. Aiming at the problem of agglomeration and damage of CNTs in the preparation of composites, the ball milling energy formula of CNTs/Cu mixed powder during ball milling was established in this paper. The relationship between ball milling parameters and dispersed structure was established by quantitative calculation of ball milling energy, and the ball milling energy equation suitable for high content CNTs/Cu composites was established. It is found that the premise of uniform distribution of CNTs in Cu powder is that the ball milling impact energy (E_p) should be controlled below 142.7 J/(g·hit). According to the critical condition of plastic deformation of Cu powder, E_p should also be controlled above 1.14 J/(g·hit), and ball milling input energy (E_t) should be controlled above 1.93 × 10¹¹ J/g. The reliability of the equation was verified by reference literature, which guided the high-quality preparation of 2 wt% CNT / Cu composites, and the hardness was increased to 2.3 times. This result provides an experimental and theoretical basis for the optimization of ball milling process and the study of low damage dispersion mechanism of high content CNTs in metal matrix composites.