Microstructure Evolution and Mechanical Behavior of CNTs/ AZ31 Magnesium Alloy Composites Processed by Equal Channel Angular Pressing
Carbon Nanotubes /AZ31 alloy composites were fabricated by joining preform of CNTs during melting under the protection of Ar. Composites were prepared by means of equal channel angular pressing ( ECAP) by Bc route in the die with the intersecting angle of 90°. Effects of the pressing passes on the microstructure and the mechanical properties of composites during ECAP were investigated; The fractographs were observed and analyzed via scanning electron microscope (SEM). The results indicate that a great deal of ultra-fine grains appear in CNTs/AZ31 Alloy Composites just after one pass of ECAP; With the increase of pass number, the proportion of ultra-fine grain increases. With 4 pressing passes, the grains are effectively refined to a mean size of 2 μm. And with increasing in the pressing passes, elongation of the composites is increased and the tensile strength is decreased as a result of the refinement of grain size. CNTs were broken under high shearing stress, and the particle distribution in the matrix alloy was homogeneous.
Zhengyi Jiang and Chunliang Zhang
G. H. Zhou et al., "Microstructure Evolution and Mechanical Behavior of CNTs/ AZ31 Magnesium Alloy Composites Processed by Equal Channel Angular Pressing", Advanced Materials Research, Vols. 97-101, pp. 1628-1632, 2010