Joining of Aluminium Alloy (AA6061-T6) to Pre-Threaded Pure Copper by Friction Spot Lap joining (FSpLJ) Process

Objective - The objective of this study is to join Aluminum alloy type (AA6061-T6) of (1.5) mm thickness to pre-threaded pure copper of (2) mm thickness applying the frictional spot lap joining (FSpLJ) technique. Styling - All specimen aluminium and copper was prepared by cutting them by dimensions (100×25) mm, pure copper samples (2) mm thickness were pre-punctured with a diameter of (4) mm and then threaded it with a diameter of (4.8) mm, a tooth step (1) mm, a rotational instrument with a (10) mm diameter was used for the joining operation. Configuration - The threaded copper was put in the mold channel, placing aluminum on top of the copper, putting the fastener over the sample, and placing the top cover of the template and fixation it with three bolts. Approach - The process parameters [rotating speed (RPM), plunging depth (mm), and pre-heating time (sec.)] was optimized by using Taguchi style, there were four levels for each parameter. The influence of the operation parameters on the joint shear strength was analyzed. The tests [Visual examination, shear force, macrostructure, and the microstructure of the joint were applied]. Results – AA6061 was extruded through the pure copper hole and its interlock with the thread slot. As a result, it was obtained mechanical overlap between the extruded aluminum and the copper. The plunging depth parameter had the greatest influence on the shear strength of the joint. Increasing the plunging depth and the rotational speed of the tool was gradually increased the efficiency of the joint. The results showed that the samples failed to test shear in the zone of the lap joint. The highest shear force is (2176) N.