In this paper, the performance evaluation of Al-graphene nanoplatelets (GNP) composites surface engineered by a modified friction stir processing (FSP) is reported. Here, multiple micro channels (MCRF) are used to incorporate GNPs in the aluminium matrix instead of a single large groove (SCRF) that is usually used in conventional FSP. With the MCRF approach, ~ 18% higher peak temperature (compared to SCRF) was observed owing to the presence of aluminium sandwiched between consecutive microgrooves and higher heat accumulation in the stir zone. The MCRF approach have significantly reduced the coefficient of friction and wear rates of the processed composites by ~ 14% and ~ 57%, respectively as compared to the SCRF approach. The proposed reinforcement filling method significantly improves the particle dispersion in the matrix, which in turn changes the adhesion mode of wear in SCRF to abrasive mode in MCRF fabricated composites. The uniformly squeezed out GNP tribolayer prevented the direct metal to metal contact between composite and its counterpart which have effectively reduced the deterioration rates.

    Abstract
    1 Introduction
    2 Materials and methods
        2.1 Raw materials and FSP
        2.2 Characterization
        2.3 Tribological properties
    3 Results and discussions
        3.1 Temperature profile and Z-load variation
        3.2 Microstructural analysis
        3.3 Tribological performance of Al-GNP composite
    4 Conclusions
    References

• Abhishek Sharma(Joining and Welding Research Institute, Osaka University)
• Tanmoy Das(Department of Mechanical Engineering, Indian Institute of Technology Kharagpur)
• Jinu Paul(Department of Mechanical Engineering, Indian Institute of Technology Kharagpur, Department of Mechanical Engineering, National Institute of Technology Calicut)