Defects formation during Friction Assisted Joining of metals and semi crystalline polymers

The work aims to identify the key factors (KFs) influencing the product quality in the Friction Assisted Joining process and how these depend on the process parameters. Experimental tests were performed under low and high-speed conditions. The tests were conducted on hybrid joints made of aluminum alloy AA7075 alloy and semicrystalline Polyamide PA66. Friction Assisted Joining experiments were conducted using an instrumented CNC machine equipped with load and position sensors. The temperature variation and distribution were measured through an Infrared Camera. The influence of plunging load, tool rotation speed, plunging rate and dwell time on the quality of the joints was investigated. Single lap shear tests were conducted to determine the mechanical behavior of the joints. The results indicated that the quality of the joints is mainly determined by the processing temperature reached during the joining process. The processability window along with the onset of main adverse phenomena affecting the mechanical behavior of the joints was determined.