Carbon nanotube addition to concentrated magnesium alloy AZ81: Enhanced ductility with occasional significant increase in strength

This study is aimed at understanding the ductility enhancing function of carbon nanotube (CNT) nanoparticles in a concentrated magnesium alloy (AZ81) nanocomposite. CNT nanoparticles were selected for reinforcement purposes due to the well known lack of affinity between magnesium and carbon. The nanocomposite exhibited similar grain size and hardness to the monolithic alloy, reasonable nanoparticle distribution and non-dominant (0 0 0 2) texture in the longitudinal direction. Compared to the monolithic alloy in tension, the nanocomposite exhibited higher failure strain (+73%) without significant compromise in strength, and higher energy absorbed until fracture (EA) (+79%). Compared to the monolithic alloy in compression, the nanocomposite exhibited slightly lower failure strain (−6%) with significant compromise in strength, and slightly lower EA (−7%). The beneficial effects of CNT nanoparticle addition on tensile ductility enhancement (with occasional drastic increase in strength) of AZ81 alloy is discussed in this paper.