Author: Peter J. DitzelPublisher:
ISBN:
Category :
Languages : en
Pages : 278
Book Description
Abstract: Friction stir welding is a process with significant potential to eliminate difficulties such as solidification cracking, porosity, and spatter which are often associated with fusion welding of aluminum alloys. Despite the advantages of friction stir welding, local variations in the weld and HAZ microstructure can limit the mechanical properties, introduce defects or present difficulties during welding itself. This work was an investigation into the metallurgical aspects of friction stir welding focusing on microstructure evolution and the relationship between the microstructures developed and weld mechanical properties. Three alloys representative of different alloying systems were used to compare the welding behavior of the various systems. Friction stir welds were produced in 6061 - T6, 5454 - H34, 5454 - 0 and 2195 - T8, followed by microstructural characterization and mechanical testing. Microstructure characterization consisted of optical microscopy and microhardness testing. Mechanical testing included tensile testing and bend ductility testing. The mechanical failures were characterized using optical metallography and SEM and then related to the weld microstructures. Experiments to measure the thermal cycles during welding and the material flow within the stirred region were also performed.