Transverse heterogeneity of interfacial bonding behavior during roll bonding of Cu/Al bimetallic plates

Abstract

The transverse heterogeneity of interfacial bonding behavior during roll bonding of Cu/Al bimetallic plates were studied through experimental research and numerical simulation. The experimental results showed that the bonding strength along the transverse interfacial gradually decreased from center to edge, and decrease accelerates near the edge. Combining with the results of numerical simulation, it was found that the variation of bonding strength along the transverse interfacial appeared to be the result of the synergistic effect of the normal stress, strain and velocity field of the bonding interface. The bonding strength in the intermediate zone of the interface slowly decreased because of a decrease in the equivalent strain at the interface. The normal stress decreases rapidly near the edge of the plate which results in the rapid reduction of the bonding strength. The poor synchronism of the metal flow on both sides of the interfaces might lead to wavy interfaces, which tend to form interface defects such as cracks and gaps.