Morphology and structure of various phases at the bonding interface of Al/steel formed by explosive welding

The bonding interface of explosively-welded aluminium and steel in three ex plosive conditions have been investigated by using scanning electron micros copy, transmission electron microscopy, electron diffraction and electron p robe microanalysis methods. The results show that all the interfaces have t he shape of waves with curled front formed by process of superplasticity an d some discontinuous reacted zones. They consist of amorphous and nano size d crystals and quasi-crystals as well as the compounds such as AlFe, Al2Fe, Al3Fe and Al6Fe with various shapes. The basal steel crystal near the inte rface has structure of martensite and perlite crystals which are deformed b y the process of superplasticity. The size of reacted zone becomes large wi th increasing amount of explosive charge powder and separation of the drive r Al plate from the basal steel plate.