Interlaminar subgrain refinement in ultrasonic consolidation

摘要: This research presents microscopic evidence of dislocation propagation and sub-grain refinement in 3003-TO aluminium undergoing high frequency fully reversed loading conditions during the Ultrasonic Consolidation process. Dual Beam Focused Ion Beam etching techniques Transmission Electron Microscopy were used to characterize sub-grain size, morphology structure regions that were subjected to levels multi-axial ultrasonic micro-strain resultant plastic deformation. Deformation Affected Zone is characterized by reduced sub-grain sizes form a gradual transition into larger equiaxed grains well below the interface. While weldi~g has been explored for some time, there been little agreement on specific softening mechanisms allow an weld to occur. Usually, unexplained effect vaguely referred as "acoustic softening," or "ultrasonic softening", generic terms do not identify mechanism. This uncertainty led many disparate theories nature of ultrasonic welding. The presented interface characterization discoveries challenge many these ideas prescribes fundamental operative softening" mechanism similar character Bauschinger Effect.