Cold bonding aluminium in a Focused Ion Beam microscope: development and qualitative in-situ assessment of the microscale technique

Microscale aluminium joints have been fabricated at the solid-state by means of a novel welding technique that is here suggested. A dual-beam microscope, a FIB-SEM, has been employed both for performing the process and for in-situ observing it. In addition to allowing a better understanding of bonding mechanisms, the in-situ approach triggered a series of subsequent setup improvements which are the subject of this work. The process involves AA6082 and AA1070 aluminium alloys that are coupled by pressure and surface expansion, as it occurs at the macroscale for Cold Pressure Welded joints. High-resolution SEM micrographs of the cross section and EDS analysis on the bonded interface have led to the optimized version of the method: this appeared sufficiently replicable and almost free from massive Gallium implantation, detected instead in the previous one. Micro-cantilever bending tests plan is illustrated for the assessment of the bond mechanical properties.