Changes in the Bonding Zone of Explosively Welded Sheets

Abstract

Changes in the Bonding Zone of Explosively Welded Sheets

In the presented paper two sets of Al/Cu and Ti/Ni sheets bonded through the explosive welding process was thoroughly analyzed. A particular attention was drawn to describe the changes in microstructure and chemical composition within the volumes close to the bonding interface. Optical microscopy as well as scanning (SEM) and transmission (TEM) electron microscopy were applied in the above studies whereas strain hardening across the welding zone was determined by Vickers microhardness measurements.

Optical microscopy revealed the coexistence of wavy (dominant) and flat interfaces in both sets of plates. Electron microscopy studies showed that the interface was characterized by sharp transition between two metals. For the Cu/Al sheets local melted zones were found mainly at the front slope of the waves where fluctuations in chemical composition were observed. Melting inside intermediate layers resulted in formation of intermetallic phases of the Cu[[m]]Al[[n]]-type while in the case of Ti/Ni sheets a continuous intermetallic layer of Ti[[m]]Ni[[n]]-type delimitating both sheets was found.