Pore defects have an important effect on the mechanical properties of graphene reinforced aluminum nanocomposites. The simulation study found that the pores affect the stress distribution in the matrix of the composite. Along the stretching direction, the larger stress appears on both sides of the pore, which is the source of potential cracks. It results in a sharp decrease in the mechanical properties of the composite. The higher the porosity, the greater the tendency of pore aggregation, and the risk of material failure is higher. The stress distribution in the matrix becomes more uneven as the pore size increases, and the large strain area around the pores also increases. Composites with circular pores have a higher strength than other irregularly shaped pores. The failure mode might be pore cracking, while composites with other shape pores are more prone to interface detachment. The simulation value of the stress-strain of the composite material is in good agreement with the experimental value, but the finite element simulation value is larger than the experimental value.

Sub-micro α-Al₂O₃ polishing liquid is often used as the slurry in chemical mechanical polishing (CMP). At present, water is usually used as dispersion medium to disperse sub-micro α-Al₂O₃ powders, but the sub-micro α-Al₂O₃ powders easily subside in aqueous solution. In previous studies, researchers usually used single method to disperse superfine powders, however, the dispersion effect was non-ideal. In order to solve the difficult problem of sub-micro α-Al₂O₃ powders dispersed in water suspension, firstly, using physical method, the effects of milling time, ultrasonic time on the dispersion property of sub-micro α-Al₂O₃ powders in water suspension was studied by single factorial test. Then, using chemical method, the effects of dispersant type, dispersant concentration and pH value on the dispersion property of sub-micro α-Al₂O₃ powders in water suspension was studied by orthogonal test. Absorbance was used to evaluate the dispersion property of sub-micro α-Al₂O₃ powders. The results show that the optimal dispersing conditions are milling time 60 min, ultrasonic time 20 min, mass percent concentration of STPP 1% and pH value 9.