Understanding the Influencing Mechanism of CNTs on the Microstructures and Wear Characterization of Semi-Solid Stir Casting Al-Cu-Mg-Si Alloys

In this study, CNTs-reinforced Al-Cu-Mg-Si nanocomposites were successfully fabricated by high-energy ball milling (HEBM) combined with semi-solid stir casting. Then, the composites subjected to hot extrusion. The Microstructure and Phase analysis of CNT/Al-Cu-Mg-Si characterized an Optical microscope, Scanning Electron Microscope (SEM), XRD. Additionally, density, hardness, wear measured. results revealed that addition CNTs effectively inhibited growth α-Al grains, grains dramatically refined. dynamic recrystallization degree composite extruded rod gradually increased from 1.3% 68.4%, content 0 wt% 3.0 wt%. hardness values increase in CNTs. Moreover, friction factor rate first decreased then as increased. When 1.5CNTs added, coefficient (COF) reached minimum 0.3577 3.42 mg/km, which reduced 30.09% 73.03% compared alloy, respectively.