Bonding mechanism and preparation process of titanium/iron composite thin sheet by non-vacuum rolling

Abstract

As a new type of layered metal composite sheet, titanium/iron composite thin sheet has attracted much attention because it can meet the dual requirements of the environment and material properties. This paper reports a non-vacuum rolling method that is more suitable for preparing titanium/iron composite thin sheet in industrial production. Herein, the bonding mechanism of the layered metal composite sheet was elucidated by analyzing the forces on the sheets during the non-vacuum rolling process then it was applied to explain the influence mechanism of the rolling reduction rate on interfacial bonding properties. The titanium/iron composite thin sheet was prepared by non-vacuum rolling with a 65% rolling reduction rate, and the interfacial microstructure was studied to verify the accuracy of theoretical judgments. The results show that a shear deformation zone exists at the interface of the layered metal composite sheet in the rolling process. In this zone, the oxide film on the interface breaks, and the exposed fresh metal undergoes metallurgical bonding under the action of radial rolling force to form a composite interface. With the increase of rolling reduction rate, the range of the shear deformation zone expands, and the radial rolling force acting on the interface increase, which is the main reason for the improvement of the rolling reduction rate on the bonding effect. Shear deformation caused vast dislocations in the interface microstructure of composite sheet. The texture of the titanium layer has a certain width under the action of shear deformation. The texture of the iron layer is mainly α-fiber, caused by shear deformation. Moreover, broken oxide films and diffusion layers of titanium and iron elements were observed at the interface.