The structure effect of carbonaceous reinforcement on the microstructural characterization and mechanical behavior of AZ80 magnesium alloy

In general, individual carbonaceous reinforcements did not entirely impart their excellent mechanical properties to the Mg matrix alloy, which is mainly due to the aggregation of them. The present work explores the potential and mechanism of developed mechanical properties by adding GNPs + CNTs in the AZ80 matrix composite based on the texture and microstructural evolutions. In this work, carbonaceous hybrid reinforcement is selected to significantly improve mechanical properties by more homogeneous dispersion of them in the AZ80 alloy via simple semi-powder metallurgy and rheo casting followed by extrusion (430 °C). The results show that network structure of hybrid reinforcement has a significant effect on reduction of grain size of extruded AZ80 alloy (25%), compared to 1D and 2D carbonaceous reinforcements. In the composites, the strongest and weakest basal textures (4.7 and 3.1 multiples of random distribution, respectively) are observed in AZ80/CNT and AZ80/GNP + CNT composites, respectively. In comparison with the AZ80 alloy, the AZ80/GNP + CNT composite shows 112%, 28%, 148% and 278% improvement in TYS, UTS, TFS and toughness, respectively. The maximum improvement of CYS (15%), UCS (23%) and CFS (37%) is attained in the AZ80/GNP composite. [Display omitted] •Synergetic effect of GNPs + CNTs on the AZ80 alloy was investigated in this study.•Synergetic effect of GNPs + CNTs was observed on the grain and eutectic morphology.•Synergetic effect of GNPs + CNTs on the tensile properties was indicated in this study.•GNPs + CNTs enhanced simultaneously yield strength and toughness of AZ80 matrix alloy.•Homogenous dispersion and bridging the CNTs promoted fracture strain and toughness.