In the present work, the flake powder metallurgy as a slurry based method and the ultrasound-assisted then ball milling as a semi-wet based route were applied to.modify the carbon nanotube dispersion within the aluminium powder. For this purpose, two types of long and short fiber CNTs-COOH were selected as reinforcement to strengthen the matrix of Al powders with particle sizes of <45 and <20 mu m. The effects of morphological changes in composite constituents and the variables of each procedure such as time and rotation speed of ball milling, chemical modification of Al powder by a hydrophilic Polyvinyl alcohol, production of nano-flake Al powders and the carboxyl agent on the wall of CNTs were investigated in this research. The Al (20) and Al (45) with 1.5wt %CNTs well-dispersed nanocomposites were produced in semi-wet based process after medium energy level ball milling at 200 rpm in duration of 2 and 4 h, respectively. Also, the flaky shape morphologies of pure Al powders with large aspect ratio of 50 and 125 were obtained after the 2 h ball milling of <45 and <20 pm powders, respectively. In slurry based method, by forming the hydrogen bonding between the -OH groups of PVA and -COOH groups of multi walled CNTs, the suitable dispersion was resulted for both types of CNTs in Al flake powders with large specific surface area. The final products were studied through field emission scanning electron microscopy (FESEM). (C) 2015 Elsevier B.V. All rights reserved.