Evaluation of bond strength on deposition of aluminium 6063 alloy over EN24 medium carbon steel by friction surfacing using different mechtrode diameter

Abstract

In the present work, an experimental exploration was made to study the bond strength on solid-state coating of aluminum 6063 over EN24 carbon steel by friction surfacing process using different mechtrode diameter. Friction surfacing was carried out by different combinations of elemental process parameters with different mechtrode rods of 12 mm, 18 mm, and 24 mm in diameters. The result showed that the applied axial force and rotational speed has a strong correlation on diameter of mechtrode for obtaining a successful coating during the process. A non-contact infrared (NC-IR) thermometer provided the temperature profile, and the highest temperatures recorded were 358°C, 389°C, and 422°C for the 12 mm, 18 mm, and 24 mm rod diameters, respectively. The mechanical strength of the successful coating was analyzed using the Vickers microhardness and bending tests. The result exhibited that the coating sample obtained by the 18 mm rod diameter gave higher hardness value (142 HV at the interface) and bending strength (481 MPa at 120° bend angle) compared to coating samples obtained from the 12 mm and 24 mm rod diameters. The coating was analyzed using field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray analysis (EDAX) techniques to know the feature of microstructure and intermetallic bonding. The result revealed the formation of better martensite attributes and more oxide compounds at the interface of sample made by the 18 mm rod diameter, indicating adequate molecular interlocking between aluminium and iron particles.