The mechanism of friction bonding process is similar to
that of friction stir welding process, where parts are joined
under a certain degree of heat and mechanical load. Many
research works reported that the amount of heat energy
conducted into the aluminum workpiece significantly affects
the strength of joined section [1,2]. Moreover, by using an
accumulative roll-bonding technique [3], ultrafine grained
aluminum alloy 1100 can be processed with less alteration to
the grain size obtained in the joined zone. To determine the
quality of bonding, the ultrasonic testing method is normally
used to nondestructively specify the bonding features. The
amplitude-frequency characteristic of the ultrasonic signals is
able to indicate the quality levels of bonded section [4,5,6].
Due to the lack of insight into the friction bonding process,
an investigation into the process for bonding aluminum sheets
(1100 and 3003) was experimentally performed in this study.
The size of delamination and metallurgical microstructure