A Simplified Design of Clamping System and Fixtures for Friction Stir Welding of Aluminium Alloys

摘要

Sound friction stir welds could be attained by using an active design of backing/clamping system with a proper selection of the welding parameters. This work presented uda simplified design of fixtures and backing plates to be used for friction stir welding of aluminum alloys. The test-rig was constructed to prevent dispersal or lifting of the specimens throughout the joining process and to ensure uniform distribution of temperature along the plates. The workpieces were subjected to uniform lateral and vertical pressures by means of bolts and nuts. udCompound backing plates and pressure bars with additional side plates were included to increase the heat sink. Several coupons of dissimilar aluminum alloys AA7075 and udAA6061 were joined to inspect the validity of this design. The tests showed promising results with defectsud-udfree welds, good strength udand smooth surface finish without geometric imperfection and gap udcreation udbetween the udwelded udspecimensud. Efficiency of the joint reached its maximum value of about 82%udwith udrespect to the ultimate strength of the udAA6061udalloy at 1100 rpm rotation speed and 300 udmm/min feed. udThese results udencourage using and improving thude presentuddesign for future udstudiesudof friction stir welding