Fabrication of laminated-metal composite tubes by multi-billet rotary swaging technique

A processing technique named multi-billet rotary swaging (MBRW) has been developed to fabricate clad composites. It is capable of fabricating multi-metal composite tubes conveniently. In this paper, our rotary swaging machine and process of MBRW is introduced detailedly. Bimetal tube (Cu/Al and Ti/steel) and trilaminar metals tube (Ti/Pb/Cu) are fabricated by this process. Based on the Cu/Al preparation process and result, the composite law is analyzed deeply. It is shown that the deformation of difference layer is not synchronous. The deformation trend of Al tube changes from high to low, while the Cu tube has a stable increasing trend from the beginning to the end. The surface roughness is compared between the original tube and each step tubes. It shows that this process has the distinct advantage in getting the fine surface quality. Moreover, the interface microstructures of composited tube are observed by SEM and optical microscope. The results show that using MBRW can get good interface transition zone, which is conducive to obtain high bonding strength. The research provides the basis to the follow-up industrial production.