Microstructure and mechanical properties of simultaneously explosively-welded Steel/Cu pipes and Al/Cu pipe/rod

Through an unique manufacturing process which we call it “the Russian-doll-like experimental arrangement”, Steel/Cu pipes and Al/Cu pipe/rod are simultaneously explosively welded in a single experiment. After that, optical microscope (OM), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), longitudinal compression, transversal compression and compression-shear tests are conducted to analyze samples’ microstructure and mechanical properties. Results show that bonding interfaces of Al/Cu and Steel/Cu couples change from unstable ones, via regular/wavy ones, to final flat ones along the detonation direction. AlCu and Al2Cu are identified around the Al/Cu interface via EDS analysis, and atomic ratios of steel and copper around the Steel/Cu interface varies from 47/53 to 75/25. Samples’ yield strength/strain in longitudinal compression and transversal compression for Al/Cu couple are respectively 340 MPa/4.8% and 120 MPa/4.5%. Steel/Cu specimens’ yield strength/strain in longitudinal compression and compressive strength/failure strain in transversal compression are 598 MPa/5.8% and 90.97 MPa/21.0%, respectively.