THE INVESTIGATION AND COMPARISON OF MECHANICAL PROPERTISE AND MICROSTRUCTURE AL/CNT AND AL/CNT/AL2O3 COPMOSITES PRODUCED BY MIXED ACCUMULATIVE ROLL BOUNDING

Accmulative roll bonding prcess is one of severe plastic deformation procidures for produce high strength-ultrafine grain materials. In this investigation, the new method of mixed accumulative roll bonding was used to produce Al-based composite reinforced with carbon nanotube and alumina. This method is mixed of Continual Annealing roll Bonding and cross roll accumulative roll bonding procedures. This process has two steps. The first step is reinforcement adding with accumulative roll bonding in four rolling passes and annealing for one hour and 350°C after any pass. The next step is accumulative roll bonding without adding reinforcement and annealing. After any rolling pass, strips rotate 90^o in each step and then rolled. In this process 11 rolling passes perform on Al/ (1%wt CNT) composite and 9 rolling passes on Al/ (1%wt) CNT/ (2%wt) AL₂O₃ composite. X-ray diffraction result show that grain size is about nanometer in final rolling pass for both composite and with increase pass number increases tensile strength and elongation decrease first and then increases. strenght in Al/CNT/Al₂o₃ composite is higher than Al/CNT composite at the same rolling pass. FESEM picture show that reinforced distribution was well in final rolling pass.