Effects of electromagnetic fields on interfacial bonding strength of Ti/Al/Cu clad sheet processed by horizontal twin-roll casting

Abstract

A Ti/Al/Cu clad sheet was fabricated by using horizontal twin-roll casting (HTRC) with the application of pulsed electric field (PEF) and electromagnetic oscillation field (EOF), and the effects of different external fields on interfacial bonding strength were studied. The results show that the external electromagnetic fields have little influence on the stability of HTRC process. With the application of PEF and EOF, the width of diffusion layer at the Ti/Al and Cu/Al interface increases obviously. The interface bonding strength is significantly improved. When the EOF is applied, the electromagnetic volumetric force is generated in the liquid cavity of cast-rolling zone. Under the action of the electromagnetic volume force, aluminum melt oscillates repeatedly, which scours the surface of the strips and makes the newly formed crystal nuclei fall off the surface of strips. In addition, the oscillation effect reduces the temperature gradient at the contact area between strip and melt and slows down the solidification process, thus prolonging the contact time between aluminum and strips. All of these effects make the melt spread more sufficient on the surface of strips and promote the interdi-ffusion between atoms.As a result, more metallurgical bonding regions are formed and enhanced.

Keywords

• horizontal twin-roll casting
• ti/al/cu clad sheet
• electromagnetic field
• interfacial bonding strength