In this study, GNPs/FeCoNiCuAl particles synergistically reinforced aluminum matrix composites are developed by friction stir processing (FSP) to explore the effects of different GNPs contents (1, 3, and 5%) on the microstructure, mechanical performance, and wear resistance of the materials. The results show that the incorporation of GNPs affects the formation of the diffusion layer between the FeCoNiCuAl particles and the aluminum matrix. As the content of GNPs increases, the thickness and integrity of the diffusion layer between FeCoNiCuAl particles and aluminum matrix gradually decrease. In addition, the introduction of GNPs is beneficial in enhancing the proportion of high-angle grain boundaries in the composites, but the grain size of the specimen increases slightly to about 5.5 μm at a content of 5% GNPs. When the content of GNPs is 1%, the composites achieve the highest microhardness and the lowest specific wear rate (0.1459 × 10⁻⁶ mm3/ N·m), with the wear mechanism dominated by abrasive wear. Nonetheless, when the GNPs content in the composite increases to 5%, the thickness and integrity of the diffusion layer are minimal, causing the tensile strength of the composite to be reduced to 250 MPa, and the specific wear rate increased to 0.4244 × 10– 6 ( mm3/N·m), with the wear mechanism transformed to abrasive–adhesive mixed wear. This study demonstrates that the appropriate ratio of GNPs and FeCoNiCuAl particles can effectively enhance the mechanical and wear resistance properties of aluminum matrix composites, providing a theoretical basis for the design and development of high-performance aluminum matrix composites.

Effect of introduction of graphene nanoplatelets (GNPs) on the microstructure, mechanical properties, and wear resistance of FeCoNiCuAl particles reinforcing aluminum matrix composites via friction stir processing
    Abstract
    1 Introduction
    2 Materials and methods
    3 Results and discussion
        3.1 Microstructure evolution
        3.2 Mechanical properties
            3.2.1 Microhardness
            3.2.2 Tensile properties
            3.2.3 Fracture morphology
        3.3 Wear behavior analysis
            3.3.1 Friction coefficient and specific wear rate
            3.3.2 Wear morphology and mechanism
    4 Conclusion
    Acknowledgements 
    References

• Dongchen Zhao(College of Mechanical and Electrical Engineering, Jilin University of Chemical Technology, Jilin 132022, China)
• Xiaofeng Yu(College of Mechanical and Electrical Engineering, Jilin University of Chemical Technology, Jilin 132022, China) Corresponding author
• Zhongyuan Suo(College of Mechanical and Electrical Engineering, Jilin University of Chemical Technology, Jilin 132022, China)
• Tingqu Li(College of Mechanical and Electrical Engineering, Jilin University of Chemical Technology, Jilin 132022, China)
• Baoming Yao(College of Mechanical and Electrical Engineering, Jilin University of Chemical Technology, Jilin 132022, China)
• Zihao Chen(College of Mechanical and Electrical Engineering, Jilin University of Chemical Technology, Jilin 132022, China)
• Jizhao Yu(College of Mechanical and Electrical Engineering, Jilin University of Chemical Technology, Jilin 132022, China)
• Wencui Xiu(JiLin Agricultural Science and Technology University, Jilin, China)