Effect of melt pressure on interfacial bonding strength of horizontal twin-roll casting Ti/Al composite plate

Abstract

Besides cast-rolling speed and casting temperature， the melt pressure in the cast-rolling zone is also an important factor affecting the process stability and interfacial bonding strength of horizontal two-roll cast Ti/Al composite plate. In this study， several Ti/Al composite plates were prepared under different melt pressures in the cast-rolling zone by adjusting the liquid level of the melt in the sluice during the cast-rolling composite process. The microstructure and interfacial bonding properties of the composite plates were characterized by metallography， scanning electron microscopy， microhardness， tensile test and T-type peeling test at room temperature. Results show that when the melt pressure is relatively high， composite plate with full filling， good plate shape and high bonding strength can be produced successfully. However， excessively high melt pressure will affect the stability of the cast-rolling composite process. When the melt pressure is too low， the transverse flow capacity of the melt decreases. As a result， the cast-rolling zone cannot be completely filled with the melt， and the defects such as misrun and side penetration occur. At the same time， some micropores and microcracks appear on the Ti/Al interface. Under relatively high melt pressure， the solid/liquid contact distance is long. In this condition， the wetting between the strip surface and the melt is more sufficient， the melt is more evenly distributed， and the diffusion between solid and liquid is more sufficient. As a result， the composite plate has high bonding strength， which reaches 20.1 N/mm.

Keywords

• cast-rolling bonding
• ti/al composite plate
• melt pressure
• interfacial bonding strength