Correlation Between Friction Time, Rotational Speed, and Mechanical Properties in Aluminum-Based Friction Welding Processes

In friction welding, rotational speed is a critical parameter that influences the welding outcomes by interacting with time and temperature variables. This study investigates the effects of varying friction times on the microstructure, hardness, and mechanical properties of friction-welded aluminum alloys. The experiments involved analyzing samples using Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS) to assess elemental composition, alongside measuring hardness, stress, and strain values. Microstructural analysis revealed that a rotation duration of 7 s produced finer grain boundaries than those observed at 3 and 5 s, correlating with enhanced mechanical properties. At a rotational speed of 1450 rpm with a friction time of 3 s, the maximum stress and strain values reached 192.85 MPa and 19.48%, respectively. Increasing the friction time to 5 s resulted in a maximum stress of 196.60 MPa and a strain value of 17.50%, while at 7 s, the maximum stress reached 194.64 MPa with a strain of 17.66%. Findings indicate that prolonged friction time tends to increase material brittleness. Hardness testing at 1450 rpm revealed values of 73.59 VHN at 3 s, 70.23 VHN at 5 s, and 79.47 VHN at 7 s, with increased rotation time resulting in finer grain structure and improved hardness. SEM-EDS analysis across all conditions (3, 5, and 7 s) consistently identified aluminum (Al) as the primary elemental constituent, reflective of the base alloy composition. These results highlight the influence of friction time and rotational speed on the material’s microstructural integrity and mechanical performance in friction welding applications.